How would you bring wealth back to the past?

Edit: A few people have argued that this question is off-topic, and as I write this it looks like it will be closed soon. However, I have written a new (and hopefully better) version of the question at How could an inter-temporal banking system work?, and I hope that you will take a look there.

Original question below:

Suppose you have a working time machine. You decide to go back 50 years and buy a house; after all, in 1968 the average cost of a new house was just about $15,000, quite a bargain! The problem: How do you transfer$15,000 back in time with you? Cash, obviously, won't work, unless you somehow have access to paper currency that was printed before 1968. (Not likely: the lifespan of paper money is ~10-15 years, so good luck finding large quantities of 50-year-old cash.)

Maybe you could bring gold back with you? Not a good idea -- gold currently costs about 30 times more per ounce than it did in 1968, so in order to have bring back enough gold to buy a \$15,000 house, you'd need to start with$450,000 worth of gold.

So -- how would you transport $15,000 worth of wealth back in time with you to 1968? Edited: Many of the answers below are really addressing the broader question "How could you get rich using time travel?" Quite a few of them actually involve transferring wealth from the past to the present, or from the further past to the more recent past. The question was intended to be more specific than that; if it helps to focus, suppose you have a single-use time machine, and that you are planning to travel to 1968 and retire there. The cost of living then is relatively low; you just need to figure out how to get your 2018 wealth back to 1968 in a usable form. "Buy something that's cheap now but expensive then" is a good model, but what, specifically, could you bring and sell in sufficient quantities? • Comments are not for extended discussion; this conversation has been moved to chat. – James Jun 4 '18 at 14:35 • @mweiss The edit adds good limits, things that I personally assumed was the restriction from the beginning (otherwise the question would not make sense), but caused a lot of pointless answers. However, it would be better if you could incorporate the new information into the actual question. If someone cares about what's edited or not, they can use the built-in edit history. Make the question look like it was written from scratch. – pipe Jun 5 '18 at 10:59 • Could someone please explain to me how this is about building a world, rather than an element of a story set within a fictional world? "Too story-based" is a specific close reason, and elements of plot or actions of individual characters are both specifically off topic (and have been since the beginning); see the Help center. – a CVn Jun 5 '18 at 13:09 • For those who object that this question is off-topic, I have written a new one that I hope is more within the scope of the site: worldbuilding.stackexchange.com/questions/114178/…. – mweiss Jun 5 '18 at 17:58 • What about a proof of Fermant's last theorem to claim the Wolfskehl prize? – StrongBad Jun 7 '18 at 1:32 22 Answers Knowledge. Bringing wealth to the past requires simply knowledge. You have the outcome of horse races, lotteries, inventions, share prices, stock market falls etc etc etc. Your head could easily hold enough information to make you rich beyond your wildest dreams if you can go back in time........ • Working for a day, begging for a couple of hours, mugging someone, selling your watch or bringing some 1960 cash. Any amount will do because you can increase it's value exponentially. – Thorne Jun 4 '18 at 0:34 • This also moves the requirement. You don't need \$15k. You could buy an ounce of gold for \$1500, sell it for \$30 in the past, turn the \$30 into \$1500 by one longshot bet at the track. Then keep increasing it. You might be able to do even better with some quarters. Not the really rare and valuable ones. Just some regular but old quarters. Pay $3-5 each. You only need a few dollars to get started. – Brythan Jun 4 '18 at 2:49 • @SimonBaars If you only make longshot bets in smaller(ish) quantities, your impact would be minimal. People were still making the bets (most likely on the other side), and lost that money regardless. Only difference is that the house has to split some of their profits with a new person that wasn't there before. If you spread your bets around so that you aren't affecting one 'house' too much and your bets are massive (which would be suspicious anyway and thus should be avoided) it shouldn't be a big deal. – Doc Jun 4 '18 at 14:35 • @ShawnV.Wilson The converse could also work. Become a bookie, and offer a really good payout on the horses that are the favorites to win, but in races where you know the real winner was a longshot (for which you only give moderately worse payouts than other betting houses, so few people bet on the winner at your place). A big win is rare enough to be noticeable, but a large number of small losses is business as usual. You collect on the losses and don't have to pay out many winners. – Ray Jun 4 '18 at 19:16 • Careful not to bet (and win) too much in the same place, or piss off the mob – Jason_c_o Jun 4 '18 at 23:30 You're incorrect about bringing cash back to the past. You could easily bring back 15,000 in \$2 bills. Back in the 1950s the US government decreased the printing output of \$2 bills, causing people to hoard them. So many were hoarded, that they are not in the least bit rare. The vast majority of \$2 bills, even from the 1950s are worth \$2. These old bills are so common, they are at face value. Most people don't even realize the \$2 bill has never gone out of circulation and is printed to this day, making 1% of all US paper currency. If you put in some time and effort, you an easily acquire 7,500 \$2 bills that are old enough to be valid 50 years ago. In addition to paper money, there are coins. Coins will stay in circulation until they are physically worn out and sent back to the US Treasury by a bank. It is extremely common to find a coins over 50 years old still in circulation. While it would be a pain to carry \$15,000 in change, even quarters, it is technically possible.

I just rummaged through my coin and money collection and found my a binder full of \$2 bills ranging from the 1800s to the 1970s. Sadly, only the oldest ones are worth more than \$2 and most of them not by much. I also have countless US Bicentennial quarters from 1976. The mint actually produced more of these quarters than regular quarters and they are also extremely common. They are worth a whopping 25 cents apiece.

• You can include \$by typing a backslash first. – mweiss Jun 3 '18 at 23:39 • @Keltari, the reason the$ breaks the text is because two of those, no matter how far apart, begin a MathJax equation. For info on this and how to incorporate it and avoid it in your answers/questions, see this FAQ on Meta – FoxElemental Jun 3 '18 at 23:57
• If you put in some time and effort, you an easily acquire 7,500 $2 bills that are old enough to be valid 50 years ago. What is the printing year? Because if it's too close to the buying-house year, wouldn't it be suspicious to pay a house in$2 bills in cash, which were printed, say, 3 years ago but look (has the wear and tear of) 50+ years old? – xDaizu Jun 4 '18 at 7:13
• @xDaizu You could deposit them in a bank over the course of a few weeks or just buy stuff and keep the change. Not ideal, but possible. – Clearer Jun 4 '18 at 7:26
• For fresher-looking bills you could do the trip in several hops. Go back 20 years, exchange your cash from the present for cash in circulation back then, and repeat. You might even end up exchanging for the same bill at an earlier point in its life! This also allows you to go further back, by gradually exchanging cash at each stop on the way. – anaximander Jun 4 '18 at 8:32

Synthetic Diamonds

Have a lab make you a couple kilos of 1.0 to 2.0 carat flawless synthetic diamonds. Have them cut to optimal brilliance then take them back to the 1960s. Visit high end jewelers in a large metropolitan area. The quality of the gems should speak for themselves. After that, the rest is just haggling. Even if the jeweler is able to talk you down, you don't care because any price that they ask will be a huge profit for you.

If the diamond is large enough, you should be able to make a considerable sum on just one to the right buyer. In 2018 dollars and market, a 2.0 carat diamond will cost upwards of \$15K. You also don't want really large stones because the market for exceptionally large gems is very small. You want liquidity to get the cash for your house, not to get into the diamond trade (which is a bloody bloody affair.) Make sure that the lab doesn't work for deBeers since synthetic diamonds will often have a fingerprint in the diamond to identify it as synthetic. We want true flawless diamonds, not fingerprinted. Retirement A few kilograms of diamonds should be plenty of wealth to live on for the remainder of your natural life. Don't live in the cities so you get atmospheric lead poisoning. Your stash of diamonds is easily worth tens to hundreds of millions depending on current prices. Also, given that your stash is just a tiny fraction of world output, no one is going to come back to you if you sell a few. • Also make sure you don't attract the attention of deBeers when you're selling. If they think you're a competitor, they'll have you killed. – Perkins Jun 4 '18 at 23:14 • @Perkins if you make it clear you only have a limited supply, deBeers probably won't come looking for you. A stone or three isn't going to hurt them. Besides, you aren't advertising that you can make flawless diamonds at will. – Green Jun 5 '18 at 12:09 • Would they have the technology to check for synthetic diamonds in 1968? – user2813274 Jun 5 '18 at 14:34 • @user2813274 They certainly would have the chemistry to find out the purity of the diamond but Carbon Vapor Deposition processes didn't become feasible till the 1980s. Creating synth-diamonds started in the 1950s but synth-diamond gems didn't show up till the 1980s or 1990s, depending on the process. It wouldn't even enter the jewelers mind that these diamonds might be man-made. – Green Jun 5 '18 at 16:46 • This is a smart idea. – Phil M Jun 5 '18 at 19:17 Take a calculator A Ti-84 will do nicely. In 1968, some of the largest, most expensive equipment was computing equipment. The transistor had only been invented in 1959. Integrated circuits are only 1966. Computers in the late 60s were the size of refrigerators. As a time traveler, you can carry back things that are far more valuable than gold. Far, far more. Just take back any modern graphing calculator. Bring back a few actually. If you can contact IBM or DEC, you should be able to sell one of those calculators for millions of dollars, easy. Just that little calculator represents decades of software and hardware advances that they would give their arms and legs for. Much of the hardware they won't be able to duplicate but a sufficiently motivated engineering staff would make huge strides. You can probably get a better offer by playing IBM and DEC off each other. Avoid selling to the government because they'll just lock you up and appropriate the calculators. Not ideal. Negotiations Negotiating for wealth transfer will take some care. These are a set of minimal steps that should be taken. Remember that the devices you hold will look fancy to any normal person who sees them. They probably won't know what they're even looking at unless you turn it on, maybe not even then. In the 1960s there's maybe a few tens of thousands who will understand and appreciate what you have to show them. 1. Buy 10 Ti-84s. Take them with you when you jump back to the 1960s. Rig each calculator with an internal acid bomb that will destroy the internal electronics after a certain period. 2. Take some form of identity to open a safe deposit box with. Maybe take a little gold as collateral. 3. Open three safe deposit boxes at three different banks in three different towns. Divide the calculators between those deposit boxes. 4. Hire the best 1960s contract lawyer you can find. You will need them to act as your agent. 5. Find a bank that will let you use their back room. Pay them in gold. Rent one of their deposit boxes too so the calculator doesn't need to leave the bank to be secured. Under no circumstances are you to take these devices onto IBM or DEC property. You have very little physical strength there. Do not give up that advantage. 6. Find an electrical engineer at IBM or DEC. Avoid all military and governmental contacts. Don't worry about meeting with managers yet. 7. Invite them to meet you at the bank for a demo of an electronic sliderule. The bank will lend credibility to your claims and also assure them of their physical security. 8. For the demo itself, just let them play with the calculator. Maybe provide them with the calculator's manual too. Have a slide rule on hand for quick verification. Keep this demo short. Any engineer worth their salt should go absolutely bonkers with this kind of capability in their hands. Expect the kind of emotional response from the engineer that people had when the iPhone first came out. 9. Give the engineer your lawyer's card. Tell them that you have a limited number of these devices available and will be putting them up for sale. Also say that you are looking for bids from multiple companies. State your opening bid. Make it at least US\$10M. Should they be interested, they should contact your lawyer. The engineer will be dumbstruck but tell him the innovations contained in this device are easily worth tens of billions.
10. You will likely have to give demos to multiple levels of management. Do not meet anywhere besides the bank.
11. Expect all manner of shenanigans in various attempts to get these devices from you. Why pay \$10M when you can just rob someone and get it for basically free? Maintain your physical security at all times. 12. Expect all kinds of delay tactics to draw out negotiations. Set a quick expiration date for the negotiations. Ensure that the calculators will self destruct shortly after the availability window. They aren't worth much to you but invaluable. Any intimations that they just can't pay are bull-hocky. IBM made US\$871M in profits. A mere \$10M for a device that's thirty or forty years advanced is laughably cheap. 13. The contract will be simple. Foreach calculator transferred, the buyer will pay \$10M, transferred to this bank. On day of transfer, the buyer will verify operation of the calculator then it will go into an escrow deposit box controlled by the bank. Make sure to disable the self-destruct device before transfer to the escrow box. The bank will handle the escrow process after that.
14. After purchase, transfer the funds to lots of different accounts. Switzerland sounds lovely.

On second thought, this is really complicated. Just take back a highly valuable resource (gold, diamonds, knowledge) and sell them for cheap. At low enough prices, all assets are highly liquid and other than authenticity claims, no one will ask how you got them.

Retirement

Since you're retiring here, you could probably get a job with IBM/DEC as a "Future Consultant". Any modern skilled profession will have meaningful contributions to make in the 1960s and 1970s.

• I probably should have specified in the problem "without drastically changing the course of history". :) – mweiss Jun 4 '18 at 3:19
• Even if you don't care about altering the course of history, selling pieces of "magical" technology seems like it may attract a lot of unwanted attention. – Johnny Jun 4 '18 at 5:15
• Do you want Terminators? Because this is how you get terminators. – xDaizu Jun 4 '18 at 7:15
• Where does one get an ID that is appropriate for 1968? – Azor Ahai Jun 4 '18 at 15:31
• They may not be able to analyze the calculators sufficiently to replicate them, but even having just a few of them to use for engineering work would be a massive advantage. A TI-86 is roughly 8x faster than the computer used to calculate the trajectories for the Apollo program, and is portable. Of course somebody is going to rat you out for peddling obviously-stolen, classified hardware and the Feds are going to grab both you and your devices and beat you with a rubber hose until you tell them how to disable the acid and then keep you in a dark hole until you die. So not the best plan. – Perkins Jun 4 '18 at 23:09

Go back further in time. Fifty years ago you might have trouble finding something that is cheap now but expensive then. If you go farther back, that becomes easy.

Aluminum

According to this answer to another question:

emperor Napoleon III reserved a prized set of aluminum cutlery for special guests at banquets. (Less favored guests used gold knives and forks.)

Modernly aluminum is cheap (we make soda pop cans out of it). So buy some ornate but inexpensive aluminum cutlery and go back in time to sell it to Napoleon. Napoleon pays in gold.

Buy paintings with the gold. For example, Vincent van Gogh was all but starving while alive. He'd have sold practically any painting for peanuts. French coins from Napoleon's time would still be worth at least their gold weight if not more to collectors.

Art supplies

Heck, van Gogh would probably have traded paintings for art supplies: canvas, oils, etc.

According to Wikipedia:

So I went into my basement one day, picked up all drawings that were somewhat offensive, put them in a big bag and when that bag was full, I brought it to the paper factory of Tilburg to be ground to paper; I've had a few dimes for it.

So if you can find a few dimes, you could buy a bagful of van Gogh nudes.

Steel

Take a modern steel katana or broadsword and sell it to a Roman emperor. Use the proceeds to buy statuary. Store the statuary somewhere that you know will persist. Unearth and sell it in 1968.

Spices

Spices used to be incredibly expensive. Some were shipped overland from China. Get paid in gold and bury the gold. Dig it up in 1968.

Diamonds

They used to find diamonds on the surface of the ground in South Africa. E.g. Big Hole:

It all began as far back as 1866 when a man called Erasmus Jacobs found what he took for a shiny pebble on the Orange River banks. To cut a long story short, it was later sold in London, after it was determined to be a 21.25 carat diamond, for £500. After a further two diamonds were found in the area, a diamond rush ensued and miners arrived in their thousands. The hill disappeared in a flurry of prospection, as picks and shovels yielded 2 722 kilograms of diamonds.

Use your modern knowledge to find the diamonds first. Sell a diamond so as to make your claim for land. Once you own the land, you can sell it or partner with someone.

• You can probably swing something 'sufficiently advanced' as 'magic'. Selling a 'magic' sword (or armour) that's way better than anything contemporary for a really high price. – Sobrique Jun 4 '18 at 15:47
• If you buy all the to-be-famous van Gogh's paintings and take them with you to the future, those painting won't become famous in the future. – Headcrab Jun 5 '18 at 6:16
• @Headcrab - the key is obtaining unknown works by van Gogh, et al. Presuming they're stored well, they can age properly, and their veracity can be proven. Bring them to the present quickly, and the paint, paper and canvas will have not aged at all, making their provenance risky at best. – VBartilucci Jun 5 '18 at 18:18
• @VBartilucci I heard, painters sometimes created several versions of the same painting, of different sizes etc. Find works of van Gogh that you know are to become famous, order such copies from van Gogh himself, pay him with peanuts. – Headcrab Jun 6 '18 at 1:53
• @VBartilucci this is why my Hitler paintings never sold for much: tor.com/2011/08/31/wikihistory – BlackVegetable Jun 6 '18 at 2:04

Just to answer the question and not verify it sense (after all why only 15K to buy house when you can own Wall street).

Look at this

To have 15K in 1968 you need around 681 pieces of 2n5085 transistors. Prices taken from Fairchild Semiconductor price list 1968

• So long as the properties have not changed enough to render them useless or the materials so much as to raise questions, this is the best answer. – Engineer Toast Jun 4 '18 at 13:48
• @EngineerToast I found on some site those Fairchild transistors. I assume technology of production didn't changed enough to create difference between 20018 and 1968 one. – SZCZERZO KŁY Jun 4 '18 at 13:57
• @SZCZERZOKŁY they'll have post-1968 manufacture dates though, unless you can dig up a bunch of really old ones from somewhere... or maybe just burn/scratch the markings off, but then you'll likely be subject to more scrutiny. – Zac Faragher Jun 5 '18 at 7:20
• @ZacFaragher transistor don't have manufacture date printed on them. Just model name. – SZCZERZO KŁY Jun 5 '18 at 7:43
• @SZCZERZOKŁY They usually have a batch number. Packages have also changed massively - Digikey does have some TO-3 chips for sale, though, but I can't find any model numbers that match. – Someone Somewhere Jun 5 '18 at 10:06

Bringing back weird oddities like calculators or transistors is going to cause questions. Even something which is available but expensive is unlikely to be in the hands of a private individual in significant quantities (e.g. the transistors), so as soon as any questions are asked, you've got no trail as to where they came from, so they'll (at best) look stolen.

The simple answer is to forge old cash. The forging technology available now would exceed the detection capability in 1968, and whilst (depending on your jurisdiction) forging out-of-circulation currency may still be a crime, if you’re caught it’s probably much easier to explain as a “historical project” or for re-enactment etc. Crucially though the materials needed to forge out-of-date currency are probably not controlled any more, so you won’t get on any watch-lists buying them.

• That definitely seems the simplest option – Mohirl Jun 7 '18 at 14:14

How about things that got cheaper? A bale of Nylon or other specialist plastics, rare earth metals. Maybe simple electronics. Consumer goods that were a luxury in the 50's but common these days. Also medicine. The chemicals are the same but you might be able to find things where the patent lapsed and are now a lot cheaper.

• This works, but for best results the time traveller must not forget to account for inflation to find the best compromise between weight/space/whatever other limitation and margin. Also, establishing a sales channel safe for time travellers (read: no questions asked, but still good price) is not trivial. – MauganRa Jun 4 '18 at 10:37
• @MauganRa Synthetic Diamonds might fit the bill here. Relatively cheap to make, at least compared to what you pay for a 'real' diamond and pretty valuable in the past. Plus, they're easy to transport. – Valthek Jun 4 '18 at 13:23
• In a sense, my original question could be interpreted as asking for specific examples of things that are cheap now but were expensive in the past (and that could be sold easily by a person arriving in 1968 with no credentials or paperwork). – mweiss Jun 4 '18 at 17:00

Your best method would be in fact, to find dollar bills that are 50 years old and take them back in time. You mention that a house in 1968 was worth only 15,000$, yet you have overlooked one extremely important factor; inflation. To drive this point home, a house in 1968 was not worth 15,000 \$ in today's currency. It was worth 15,000\$in 1968's currency. So using an inflation calculator (https://data.bls.gov/cgi-bin/cpicalc.pl), 15,000$ in 1968 is the equivalent of 110,210.85\$today. The first thing you will notice is that while this is substantially cheaper than modern housing prices, you will still only be able to get maybe 4x today's value in assets if you translated your money point for point into the older currency. So the real secret sauce is to hoard older dollar bills. It might take a bit of searching but at 7x its actual dollar for dollar amount and (7x4) 28x times its modern value when buying houses, this is probably one of the best ways to go. If you want to just take money back into the past at roughly a point-for-point value then you should focus on non-perishables. You have already mentioned gold (which hasn't really changed too much in value since 1968 after accounting for inflation). If you take gold back in time it would be best to take it back to before the discovery of North America. This is because that will be before the gold rush. So since gold was more scarce back then it would be worth a lot more. If not gold, you can pick other precious metals, and so on. A lot depends on the specifics of how you want to transfer the money back into the past. For example how far back, how much, at a profit, etc. Just don't fall into the trap of thinking that just because things were apparently cheaper back in the day, that they were actually cheaper. Often they were not in the money/effort required for that day. If you want to make money: Go back to 2009, spend 1000$ on bitcoins, and be a millionaire today. No questions asked. The currency is used for a lot of illegal activity anyway so no one will know where it came from.

Some quick math:

Price of bitcoin in 2009 = 6 cents.

Bitcoins you can buy with 1000$= 16,600. Price of bitcoin in 2017: 17000. Profit = 283.3 million - 1000$

One trip will suffice, and you can retire in the modern day.

• Now I know where those lost bitcoins went. Somebody tried this. – Joshua Jun 6 '18 at 3:49
• The question was not "how to get rich using time travel". It was "how to transfer money to the past." – mweiss Jun 7 '18 at 17:36
• @mweiss I have made another answer in your other question which discusses how you can do what you want using bonds. – Tyler S. Loeper Jun 7 '18 at 18:01
• Also I did answer the question how to move money back into the past. I would argue this question is very different from your other question where you discuss mass time travel which obviously leads to there being more and different options. – Tyler S. Loeper Jun 7 '18 at 18:40

You can just buy old money from collectors. If you use 1000 dollar bills you'll only need fairly small amount. Unfortunately prices for the latest 1934 series seem to start with 2000 dollars, so you'd pay a premium. As a bonus you can get 1934 bills fairly easily from eBay and prices are not significantly over 2000 dollars.

500 dollar bills might be cheaper. Ones printed in the 1940s are apparently not rare enough to be collectible, so you'd pay around the nominal price. These would also be what was likely to be in circulation in 1968.

It might take some time to collect the bills, but I am fairly certain money collectors have their own forums and magazines where you can advertise you are buying 1940s 500 dollar bills. For that matter any business that sells and buys old money will probably be happy to help you since they already have the needed connections and know all the right people.

• any idea how hard it would be tell the difference between a 1934 dollar bill that had aged 34 years versus one that had aged an extra 50 years? There's a noticeable difference between a book 40 and 70 year old book, but I don't know how much the unique material money gets printed on makes for aging – Foon Jun 4 '18 at 17:36
• Bills in denominations larger than $100 were generally only used for inter-bank transfers. If you show up with a bag of them people are going to get suspicious. Although you might get away with it as long as no robberies had been reported. – Perkins Jun 4 '18 at 23:18 • @Perkins, good point. But a person could go to several dozen banks over a few days getting a single large bill changed for smaller bills. This would work best if the time traveler is going around the area and not staying in a single city or town at first. – Dan Clarke Jun 5 '18 at 4:13 • @Perkins Or large purchases of property. But yes, how you bring in your wealth is a real issue not really limited to large bill denominations. Maybe scan old court records for how all the criminals did it? You'd probably also want to think about the risk of being mistaken for a communist spy. You come from nowhere with large amounts of wealth and no explanation of how you made it... Claim to be American but do not speak right or know things literally everyone knows. If you have a solid identity, using large bills probably is not an issue. If not it is not your biggest issue. – Ville Niemi Jun 5 '18 at 14:00 • @Foon That's the beauty of the money being contemporary to the "locals". They won't scrutinize it the way collectors today would. Counterfeiting wasn't very sophisticated back then, so as long as the money looked real, I don't think anyone would even notice some lack of wear. – Quasi_Stomach Jun 5 '18 at 16:42 One very important point when trying to pull a cross-time investment scheme. Don't forget about the five year rule. For all the suggestions about investing, putting money in the bank, etc, almost all banks have rules about orphaned accounts. If an account, a safe deposit box, whatever, is left untouched for a period of time, the bank may seize the assets. They're required to try to find the owners, which used to be done by taking out newspaper ads and other public notices; they probably do it on the web now. So if you put the money in a bank and come back fifty years later, that money will almost certainly be gone, long since absorbed by the bank. You'd either have to make a very unique arrangement with the institution (which they'll probably STILL try to get out of after thirty or forty years have passed) or you'd have to pop by every three or four years on the outside to get the interest posted in the passbook or whatever to keep the account active. You'll almost certainly have to arrange some paperwork along the way to record the transfer of the assets from you to from your "father" or "grandfather", after whom you were named, and yes, I do resemble him quite a bit, I get that a lot. • The question was not "how to get rich using time travel". It was "how to transfer money to the past." – mweiss Jun 7 '18 at 17:37 The simpelest way may be creating a series of small jumps to get 'current-day' currency. Inflation being what it is, taking back gold or another similarly precious material is either going to be uneconomical or hugely impractical. What I'd propose is to go around and get the oldest dollar (or whatever the currency is in your world) bills or coins you can find that are still going for 1\$ per \$. Collect a suitably large amount of them (15.000\$ worth) in your case. Go back in time to a year after when they were printed and exchange them for older bills of the same value. Keep in mind that you may lose a small percentage of your seed money to living expenses and exchange fees, so bring a little more than you think you'll need. At a 2% exchange fee, you'll need just under 16.240\$to start with. Fire up the machine again and go back in time, repeating the process. Near as I can tell, most bills tend to stay in circulation for 12-ish years, so you'll probably need 5 jumps to get back to 1968. Once there, you'll have your 15.000 in cash to pay for a house. It may be worth the effort to exchange at least a part of your 10-year old bills printed last year once there. Otherwise, the house's seller may ask questions as to why you're paying cash for a house with suspiciously old-looking bills. Don't forgot you're going back in time... then coming back to the present If my understanding of the question is correct, the aim is to be able to have/afford a house in present day but only pay$15,000 for it, or at least pay as little as possible, and you have access to a time machine of some sort that can take you back 50 years, I'm not sure if that's only 50 years or it can do more or less as well. but I digress, if that is the case

Although Gold is worth a lot less dollars 50 years ago, due to inflation of the Dollar not value of Gold. it is still the most hassle free way to transport wealth back in time. It's how you use it that counts

So Today Gold is roughly 1200 Dollars an ounce, and back in 1968 it was roughly 290 Dollars an ounce, so if you were to buy 12,000 Dollars worth of Gold today, you'd have roughly 2900 Dollars in 1968, not great but... as others have suggested, you can get old money now, you might have to pay twice as much for it, but if nothing else you know Gold is going to be worth 4x what it was worth then, so spend as much money now to get the old bills, go back and spend all that money on Gold then bring it back and sell it...

Alternately...

In theory, you could buy $10,000 worth of gold today go back in time and then sell that and place the money into stocks that you know full well will mature well over time. you may only be able to but a few different stocks but buy a few here and there and as they mature they split doubling your amount, then have dividends placed into a couple savings accounts. this is important as account that don't get accessed every few years get flagged for checking, and if they don't get used after this then they can be closed, the money would still be owed to you but the interest rates would no longer pay out, so simply having some letters put in with a lawyer, which they will send every couple of years to transfer some money between the accounts should see you fine right up until about 2001, when banks security changed and you would have to go in to do things like this, (be aware that some small town banks still to this day will make transactions by letter) The dividends are paid on say (Very low estimate) 10 cents a share and that is usually paid 4 times a year (this changes with certain companies and requires them to always make a profit, but lets assume you did your research and knew this would happen) so 40 cents a year, for 50 years is 2000 cents, 20 dollars! yay... OK so not that much, but that's only for one share, so owning say 200 shares in company X would net you,$4,000 not bad return so far, but still not made your money back until you sell the shares. but!!! as a company matures over time they often split their shares, Microsoft for example has split their shares 9 times since 1986 to maintain a reasonable trading range

So if that were the case then those 200 shares would be if split however many times your chosen company splits (it's all in the research before you go)

No Split: 200 Shares = $4,000 1 split: 400 Shares =$8,000

2 Split: 800 Shares = $16,000 3 split: 1600 Shares =$32,000

4 Split: 3200 Shares = $64,000 etc, you see how this is going, there's no point buying the house back then when you can buy a much bigger house in the present, and that's not even taking compound interest into account, and this is only the dividend money, not the value of the shares themselves One very simple way of getting round this is if you can go back more than once,$10,000 worth of stocks in 1968, and that would net a huge amount over time in dividend payouts, Go back in 1984, and invest in Red Bull, this would increase the divided payouts even more... then go back in 2000, take those divided payouts and invest in Apple or Microsoft, then come back to the present, you wouldn't have changed much in terms of human history (let's just ignore chaos theory for this) and yet, if you take inflation, and even some very low estimates the dividend payouts alone would make you a multi millionaire

• When stocks split, their value halves (but your # holdings double). They split to keep the price of a share low enough to be easily purchased. Bringing up stock splits here really is out of context - what you really mean is that the value of your investment will go way up. – TheSoftwareJedi Jun 4 '18 at 14:57
• Berkshire Hathaway (BRK.A) stock was around 290 in March 1980 and is 290,000 in June 2018. The IPO was for 19 in 1964. – Tangurena Jun 4 '18 at 15:10
• @SoftwareJedi, my figures were for the potential dividend payout over 50 years, not value of stock. i'm aware that splits are designed to keep a companies stock within a reasonable trading range, thats why i just did the maths on potential divivdends – Blade Wraith Jun 5 '18 at 6:52
• Stock splits don't help with dividends either. The company will make the same amount of profit whether it's legally divided into 10 stock or 10,000,000,000. Dividends are typically paid from company profits, so what matters is how much profit the company makes, not how many stocks it is split up into. – a CVn Jun 5 '18 at 11:43
• @MichaelKjörling, which is why i gave very low estimates on stock payouts to give only a baseline from which to start and stated it was all down to the research before you went back. if you've enough time to try and source old bills, then you've enough time to research a companies stock history – Blade Wraith Jun 5 '18 at 14:02

You could take a copy of a few valuable patents that you could file under your own name and sell rights to interested companies. You could minimize the impact on the "timeline" by selecting patents made by large companies and selling it back to them. The result would only be extracting a couple million from large companies like IBM, General Motors etc which wouldn't redirect the course of history.

• Hello Capa, and welcome to Worldbuilding. This looks like the seed of a good answer, but we discourage one-line answers on this site. Perhaps you could edit to expand on what patents would be useful, or specify more details. Please check out our help center and take the tour for more information on how the site works. Have a nice day! – Gryphon - Reinstate Monica Jun 4 '18 at 14:12
• I believe OP stated on another answer that he wanted to minimise any impact on the future, which would exclude this option. – F1Krazy Jun 4 '18 at 14:19
• Heinlein wrote a novel with this as a plot element. – davidbak Jun 5 '18 at 5:13

I would like to disagree with the answers that say you can in fact bring 15,000 cash back in time. Or from my perspective, anything that was in circulation in the time you are traveling back to. This is especially important if you are trying not to disrupt (or as little as possible), the economy or events of the past. Money (and many other items) have serial numbers. If you use money printed from 1950 that you brought back from the future, there will now be duplicates of those serial numbers, and thus 15,000 into the economy that was not there previously.

Instead of bringing something that existed physically and reintroducing it as a duplicate in the past, I recommend a two part system for buying that house.

1. Learn a skill you can take back in time and easily find a job with to 'naturally' make money.
2. Bring back ample knowledge of event outcomes. Stock market, sports team betting, etc.

With these two steps you can make your own money in the time you travel to, and use knowledge from the future to make it far faster than everyone else. I think possibly important but probably out of scope is your identification as you were likely not born yet, and you are trying to work and buy a house.

• Even today, bills with duplicate serial numbers can exist for year without anyone catching them (there are some really good forgeries out there). 150 \$100 bills would never be found 50 years ago. Unless both duplicate bills were somehow involved in a crime high enough to be logged and kept in storage... no one would ever find the duplicates. Especially since they'll be removed from circulation (destroyed) in under two decades anyway. – ArmanX Jun 5 '18 at 15:11 • @ArmanX, My focus on the serial numbers was meant more so that you are introducing duplicate bills into the system - not as much about getting caught. It is up to OP if he wants to take that route. – Jordan.J.D Jun 5 '18 at 15:16 • I would think that by 1960s standards, the government would just think that the dollar bills were an amazing forgery. It might be slightly newsworthy, but probably not. – Tyler S. Loeper Jun 5 '18 at 17:02 • @TylerS.Loeper , I don't think that would be the outcome. They are not forged they are the actual same item. Regardless, I am trying to say that OP might not want to add more money into circulation. More bills == less value. – Jordan.J.D Jun 8 '18 at 15:07 Use your time machine more than once. Buy a few really old coins - at least 100 years, preferably more. Go back and invest it in a very safe bank. (You know which ones will survive the Crash :-). If you invest \$100 at that start then after 200 years at 4.0% interest you'll get nearly 300k$at the end. Go back further in time, and take back something like lace that is relatively cheap now, but expensive back then. Sell it, and then use that money to buy an "undiscovered" oil field. The move forward to the 1950's, sell your oil field for a bundle, buy your house, and for good measure, buy stocks that you know will explode in time. I agree with many of the answers that the most practical thing you can bring is knowledge. You will probably need a few strategies to earn huge amounts of money. Bring back something worth a little bit and is easily exchanged (such as gold, don't worry about the value, it is worth approximately the same then as now, adjusted for inflation, anyway, you just need seed money), then gamble in games with known outcomes to make more money, but you don't want to earn too much this way or you'll attract the wrong kind of attention. Once you have a little bit, use the money to buy supplies, transportation, etc. to help find a treasure that's already been found, but not at the time you are going back to. One example of a treasure you might be able to find: California couple finds$10 million in buried treasure while walking dog

I don't think you want to purchase property in the past since it would probably be difficult to do that without valid ID, and then claiming it when you get back to the future will probably be difficult as well, especially if you haven't been paying your property taxes. The property will likely be declared abandoned and auctioned off before you could claim it in the future.

So, with the money you get from the treasure, you can invest it in some sure-fire stock purchases (as others have mentioned). Ideally, you would get actual paper stock certificates that should still be good when you come back.

Once you have your stock certificates, come back to the present and redeem them. You will probably want to bury the certificates somewhere you can find them so they age properly. Wouldn't want them to determine they are counterfeit due to their apparent age. Also, make sure you find them somewhere that you can prove you are legally entitled to them even if you didn't purchase them (how could you have, right?).

If you're willing to go back farther in time than 50 years, then you will want to stock your time machine with soda. Specifically cans of Soda. Then travel back in time to the Napoleonic era, use the instructions to chemically extract the aluminum from the cans, and sell that. Before the synthesis of Aluminum, the metal was insanely valuable. Napoleon's finest dinner wear was made of the Aluminum and was used to impress the finest of dinner guests... the Gold Dinner wear was used for the lesser important people he had to entertain. Over in the U.S., when the Washington Monument was completed, it was capped with an ingot of Aluminum (rather than Gold) to symbolize the wealth of the nation. Today it's a fairly cheap metal and so common to find and turn back into the real stuff it can easily net you an impressive gold mine. All you have to do is avoid being noticed having so much of the stuff. Heck, you can even laugh about the whole ordeal with your time traveler's club buddies by telling them that the Aluminum used to make Napoleon's finest goblet was formerly a Mountain Dew can.

Commodities

Commodity answers to this question become much more profitable, interesting, and educational for readers the further back you go. It's fun to see how gold had a great return in pre-exploration Europe but a huge mistake in the Levant just after 1324 or the US in 1869; of course, the whole reason for the Age of Exploration was willingness to risk the lives of entire flotillas for the profit on spices—mainly pepper, cinnamon, ginger, cloves, cubeb, & galingale—in Europe after the Islamic conquest of Egypt ended Hippalus's direct route to India but before the final crash in the 1660s; cinnamon and cassia were pricy in Ancient Egypt because of their importance in embalming rituals; meanwhile, salt was a lucrative source of trade in West Africa, for Venice, and in China; it was never as crazy as people make it out to be but if you still want to head to 1630s Netherland if you have tulips handy; Napoleon's aluminum dishware stuck with our history buffs enough to have already shown up in 2 answers (one of them even got it right that it was post-1855 Napoleon III and not c. 1810 'Napoleon'); &c. &c. &c.

But 1968? That's already a time with fairly well developed exploration, tech, & markets. You get occasional things like the insane 2006–7 run up in uranium prices (a major Canadian mine flooded) but unit prices in real terms mostly get smaller over time except for short-term bubbles produced by speculators and by attempts to corner certain markets (fake soybeans in 1963; silver in 1979–80; copper in 1995–6; propane in 2004–6; nickel in 2006–7; &c.). Obviously you could make a fortune over a few years from some initial capital by buying up oil ahead of the 1973 OAPEC fiasco. You should certainly avoid cash in favor of securities and commodities during most of the '70s and early '80s. But there's no commodity that's sensibly portable and currently available and cheap that you could sell at a very high markup in '68.

Electronics

Green's hilarious answer above covers just how complicated this is going to be, at best, and that even the simplest products would be reverse engineered and alter a massive chunk of the future after a 5–10 window. Something as small as a decent spreadsheet program could potentially alter major elections. At worst, you out yourself as a time traveler; you'd spend the rest of your life at a black ops site run by one side of the Cold War. Word getting out of you providing anything useful under torture would mean the other side at best assassinates you; at worst, you survive and they gamble with a nuclear first strike.

Laptop

Obviously the laptop itself would represent enormous innovations and is thus hugely dangerous. Just keep it hidden, along with your surge protecter and two-prong adapter. What you're aiming for (besides having some decent games, music, and entertainment) is storing databases and algorithms.

You could keep a list of major longshot winners. Without discipline, you'd quickly have the mob or police chasing you after the first few payouts. Here's a list of recent potential time travelers; except for this guy in Staffordshire, they made a lucky hit once and not again or already had a reputation for large low-odd bets. You could hide for a while in major events—Proud Clarion was a 30:1 longshot at the '67 Kentucky Derby—but they don't offer the biggest payouts. More importantly, every win against a casino or bookie is money out of their pockets. What actually works longterm is systematic horse betting, where the house takes a cut off the top of all bets and doesn't care who wins among the punters, as long as their 'luck' isn't so egregious that it stinks of race fixing. By the 1990s, Bill Benter had an algorithmpublished in large part by World Scientific—that loses plenty but wins with enough of an edge to beat the system and rake in multimillions. Have a database and a system whose announceable process and copious losses legitimize your winnings, whether legitimate or based on your foreknowledge. (The shifts in track behavior based on your winnings would likely start reforming the races themselves, invalidating the exact records you returned with.)

With enough capital, a similar process could be done with trading algorithms used by hedge funds' automated traders. Run slower or even human-based versions of the same processes and cheats; avoid individual rocket shares but follow investment algorithms that are known to have worked consistently for your expected lifetime. Or, if you treated morality as your characters' dump stat to max out their chutzpah, pull off stock and investment scams before their expected dates. (This might be something a stock-based time traveler would have to default to, as their interference in the market began to shift investment patterns and invalidate the original expected winners.)

The most lucrative patents to take back (assuming you don't want to run your own factories or cripple the internet in its cradle by sitting on most of its processes) are going to be effective pharmaceuticals historically discovered a few years later: taxotere for cancer, lipitor for heart problems, viagra for circulation issues, &c. You can pretend you're a recluse chemist who stumbled across sth by accident. As profitable as they are, however, you're still going to need to take a small lump sum to sign over the patent or sit on it for years as you negotiate with someone who can shepherd it through FDA trials and then mass produce and market it. [You might throw in some patents for AIDS treatment, cheap DNA marker sequencing, and nixing Stanford's treatment of rDNA licensing as a humanitarian gesture, though you might be hard pressed to explain their importance.] The golden age for easy-once-you-know-it patents was the late 19th century; there are still some sitting around though. 1968 is the year a guy at 3M developed the low-tack adhesive that permitted post-its but they didn't figure out how to use it until years later; Lonnie Johnson, Sarah Blakely, and Paul Brown are still decades away from creating supersoakers, Spanx, and valve tops for ketchup and shampoo bottles but any of them could've been made or approximated in '68.

Fads are lightning in a bottle and it's hard to know if you could profit off one by coming in earlier than when they caught the Zeitgeist. Still, you've got waterbeds ('68), pet rocks ('75), mass cocaine running ('75), crack ('84), collectible card games ('93), &c. &c. that you could get an effective and immoral tout to bring out ahead of schedule.

Other answers are great. What I'd do is bring a \$2 bill and knowledge of the 'future' to go back and earn it myself. Using base 2, we can calculate that you will have to double your money 14 times to end up with 2^14 =$16,384.

If you can get more than 1 \$2 bill, you can augment the base in the equation to see how much faster you can earn your money, i.e. bringing 2x\$2 bills, the formula is now 2*(2^13) = $16,384, so essentially you require 1 less transaction. 4x\$2 bills would be 4*(2^12), 12 transactions required

8x\$2 bills would be 8*(2^11), 11 transactions required You can start to see a diminishing return, where you need to start out with exponentially more \$2 bills to keep shortening the number of doubling transactions required.

Unless you can get your hands on 16, 32, 64, 128... \$2 bills easily, probably best to just bring 1 or 2, and get the payoff from a few more required transactions. That seems like way more fun, anyway. • What's so magic about doubling your money? – pipe Jun 5 '18 at 9:23 • Never mind that, how do you actually propose to double the money a dozen times over? – a CVn Jun 5 '18 at 11:46 • No magic involved. Except the part about travelling into the past. @MichaelKjörling We know the year: 1968. To give specific examples, we would need to know the exact date of the character's return. At that point, they could do research in the present, to see for instance which horses won which races, which ball teams upset their competition, or in day trading, which stocks saw rise and fall, when to buy and when to short. They may not exactly double their money each time, but it's a solid estimate of how long/how many transactions to expect until they achieve their goal. – Bango Jun 5 '18 at 12:14 • @CactusCake Revised my answer accordingly, thanks. – Bango Jun 6 '18 at 21:44 By calculating the value of gold in the age you want to go to and bring the equivalent of$ 15.000 of that year with you? The REAL problems you'll be facing will be connected to your level of knowledge and social development. Example: Back in the '68, racism was still rampant in the US. You really wouldn't pass for a 'nigger-lover'. Also watch out for other rights you take for granted today: you'd be mistaken for some 'dirty commie'. ESPECIALLY when it comes to your schooling: you'd know things in science and history that, if caught by the wrong persons, could lead you to a world of trouble with CIA. And finally, you'd need to deposit your gold in more than one bank so not to draw unwanted attentions -I mean, imagine a mr. Smith coming to town with a cache of gold acting like it was the most normal thing.