Well I got my answer. The Wall Street Journal reports:
Risk is again a four-letter word among individual investors. That could spell further trouble for the stock market in days and weeks ahead. Already, investors pulled $2.8 billion out of U.S. equity funds in the week through May 12, according to Lipper FMI, the most since March 2009. Safe-haven money-market funds, meanwhile, saw inflows of $16.6 billion. That broke a 17-week streak of declines.
This may be the reason stocks are now retesting the closing lows seen during the crash of a couple weeks ago. Funds have to meet redemptions and with no cash on hand they are forced to sell into weakness rather than use it as a buying opportunity.