People don't treat monopoly money like real money. Stunning. Next the professor should see how risk adverse these students are with their own tuition dollars. Suddenly these kids aren't the big rollers they were with imaginary risk. Quit looking at numbers, follow the risk. Numbers are relative to risk. Consider the influence of monetary policy on risk. Does a cheaper dollar make a frugal investor? Hardly.
Especially for college students... Which is why they are so heavily marketed to by credit card companies (not to mention the entire high tuition/student loan situation).