The stock market is crashing—slowly, and in plain view of the people who count on it most. The 53% plunge in the Dow Jones industrials since October 2007 has wrecked the college- and retirement-savings plans of millions of investors. It has permanently lowered the long-term investment projections of private endowments and pension funds. It has sent corporate compensation experts scrambling to figure out how to reward top employees. All told, more than $10 trillion of stock market wealth has vanished, and with it the confidence that springs from financial security.