To sort out the competing claims between behavioral finance and efficient markets theorists, observers need to find bubbles that occur when a readily available measure of fundamental value is also observable. The bubble in closed-end country funds in the late 1980s is instructive here, as are the bubbles that occur in experimental asset markets. According to the efficient-market hypothesis, this doesn't happen, and so any data is wrong. For closed-end country funds, observers can compare the stock prices to the net asset value per share (the net value of the fund's total holdings divided by the number of shares outstanding). For experimental asset markets, observers can compare the stock prices to the expected returns from holding the stock (which the experimenter determines and communicates to the traders).