By most accounts, shares in Apple Inc. (NASDAQ: AAPL) should have gone well above $100 this week and held there. Instead, the stock trades little better than it did after its last earnings announcement in January.

Amazon.com (NASDAQ: AMZN) certainly reported a good quarter, but for its shares to be 70% higher than they were a month ago seems extreme. Google Inc. (NASDAQ: GOOG) and eBay Inc. (NASDAQ: EBAY) did well this earnings season and neither has seen anywhere near this kind of market performance.

Microsoft Corp. (NASDAQ: MSFT) has traded down most of the year. Observers would attribute that to comments that CEO Steve Ballmer made about expectations for the company's new Vista OS being too high. As it turned out, the expectations were fine. The market overreacted to Ballmer. The stock moved up on good Vista news.

General Electric Co. (NYSE: GE) is another company with strong earnings, but the stock has moved down over the last three months. That is until a Citigroup analyst raised a very old idea of breaking the company into pieces. In a day, the stock recovered all it had lost in the previous 90 days.

There is a theme in the trading of these four stocks. It's so simple as to be childish. Low expectations can give way to big yields. High expectations are hard to top. The markets expected the world of Apple. Apple delivered. The market saw no benefit in driving the stock much higher. The Mac and iPod did just great. The iPhone is on the way. No news.

Amazon has been pounded by Wall Street and the press for the last two years. The company lacks focus. It's in too many businesses. Jeff Bezos, the founder and CEO, spends too much money on marketing and building out the company's technology platform. That hurts margins. Of course, all of that is true until the day it isn't. That day fell in the middle of last week.

Douglas A. McIntyre is a partner at 24/7 Wall St.