Technical Correction
  
See: Technical Decline.
Stocks have been rising for a few weeks now. The economy is chugging. The Fed has promised to keep rates low. Everything seems set for further gains.
But then the market sees a few days of declines. Like a squall appearing suddenly on an otherwise sunny summer day.
What happened?
Technical correction. It's a situation where some buyers, holding gains from the recent advance in stocks, move to lock in profits. It doesn't signal a long-term decline. It doesn't mean the bull market is over. It's just one of those "one step back, two steps forward" types of situations. See: Paula Abdul for details.