TUMBLING SHARES: Bed Bath & Beyond's shares plunged Thursday, a day after the home goods seller issued an earnings outlook below Wall Street's expectations.

WHAT IT MEANS: Bed Bath & Beyond is a good barometer of consumers' willingness to spend on home goods. Executives told investors late Wednesday that shoppers increased their use of coupons. Weakening spending is bad news for the economic recovery because consumer spending accounts for 70 percent of U.S. economic activity.

SHARE MOVEMENT: Down more than 15 percent Thursday afternoon to $61.90, making Bed Bath and Beyond the biggest decliner in the Standard & Poor's 500 Index.