A little bad news goes a long way.

Wednesday's news from mattress company Tempur-Pedic International Inc. that it was cutting its full-year profit and revenue forcasts caused the Kentucky-based company's shares to plunge 47 percent in mid-morning trading.

CEO Mark Sarvary said in a statement sales so far this year have been "disappointing and below plan, primarily due to changes in the competitive environment."

The dire news from a rival caused shares of Plymouth-based Select Comfort Corp. to decline about 19 percent.

The overall financial picture for Select Comfort appears different from that of Tempur-Pedic's, however. In April, the Select Comfort posted its 13th consecutive quarterly profit. Last month, Chief Operating Officer Shelly Ibach, a veteran of Target Corp., Marshall Field's and Macy's, took over as CEO.

Another competitor's shares plunged, as well. Mattress Firm Holding Corp.'s stock is down 22 percent in morning training.

Janet Moore covers business for the Star Tribune.