I think such a robot would scrounge up some pocket change (say 100 loaves of bread worth of local currency) in a trivial amount of time by noticing local opportunities within the first day or so of watching human behavioral patterns.
At this point, I think he'll buy a prepaid credit card and go straight to the best form of gambling online. With superior parallel processing, substantial winnings across multiple sites funneling into multiple discreet accounts will rack up finances quickly.
With a tidy sum in tow, the robot may now move to a more advantageous location. I think he'll start working with stocks, currency trade and the global market, as in Bellerephon's answer, however I don't see a passive role.
While being discreet is a goal, the robot will have a good grasp of it'sits own abilities and how much confidence to have. With enough finances, covert identities beyond our tracking should be a breeze. Due to this I think such a bot will stimulate up and down turns in the market toward his advantage until he's got enough money to create a sustained system for..whatever whatever it needs money to do.