Advance Auto Parts is reaching oversold status from the recent fall in price. Advance Auto Parts is the weakest-looking chart by far. Based on my experience with gap downs following reductions in guidance similar to O'Reilly Automotive, investors may not see the short-term low until Thursday or more likely Friday. Wednesday's open near the 60-week moving average suggests some support near $78, but don't count on it holding. More often than not the close is below the open in situations like this. Resistance is now at $84 a share and it will take a great earnings release to breach it. Considering today's announcement is to warn of lower guidance, don't expect a beat for at least another quarter. Bargain hunters and short sellers covering positions could push the price up about 30% to 50% in relation to the gap down price this week. Round numbers often attract like a price magnet and repel, causing a bounce. Expect a lot of volume to trade near $80 a share, but also be prepared for bargain hunters to start positions under $75 as an entry. O'Reilly Automotive price-to-earnings multiple is about 20. If you are looking for today's drop to signal a buying opportunity, you are likely going to find Thursday or opening on Friday better than Wednesday. There is no hurry jumping on board with O'Reilly Automotive. Stocks dumping as a result of lowered guidance normally take a full two good earnings quarters to recover. Take your time and do your homework before allocating capital here. Look for the second break above $84 as the one that "sticks." Want to see a classic miss earnings result a few weeks after the fact? Take a look at DELL ( DELL). Dell disappointed and traded from $15 down to an intraday low of $12.31. Also, take close note of the next few days after earnings. This is a classic pattern I see often, and you can, too. Simply use your software to look at charts from the past few quarters and review the ones that gapped down the next day. The high placed a couple of days after the gap down in Dell is now resistance.