Wal-Mart's Fourth Largest Downside Gap Since 1980

After lowering earnings guidance before the market opened, shares of Wal-Mart (WMT) opened significantly lower this morning. Because expectations heading into this year were set high following last year's outperformance, this morning's news is all the more surprising, and it is causing even more selling pressure. So should investors buy or sell into today's strength?

As shown in the table below, today's downside gap of nearly 8% is the fourth largest for the stock since 1980, and the fourteenth negative gap of 5% or more. In the thirteen prior negative 5% gaps, the stock has averaged an intraday gain of 3.4% with positive returns 54% of the time.