I believe that the biggest factor in a stock's ability to beat the market is to beat the market's expectations. That's why I look every week at three companies that have humbled Wall Street's pros over the past few trading days. If a company has more in the tank than the analysts figured, capital appreciation often follows.

We can start with Dell (NASDAQ:DELL). The computer giant posted a fiscal-second-quarter profit of $0.28 a share before one-time charges, good enough to barrel past analyst expectations of $0.23 a share on the bottom line. Revenue also clocked in ahead of Mr. Market's projections.

This isn't a revenue growth story. It will take time before Dell begins growing its top line again. However, the company is committed to eliminating $4 billion in annual costs by the end of the next fiscal year. 

Dollar Tree Stores (NASDAQ:DLTR) hit a 52-week high after the discounter crushed the pros. The thrifty retailer earned $0.63 a share in its latest quarter, comfortably ahead of both the $0.42 it earned a year earlier and the $0.54 guesstimate from Wall Street.

Shoppers love bargains in a dour economy, so it's not a surprise to see Dollar Tree join other discounters such as Big Lots (NYSE:BIG), DSW (NYSE:DSW), and Tuesday Morning (NASDAQ:TUES) by checking in with better-than-expected quarterly results in recent days.

Finally, we have Corinthian Colleges (NASDAQ:COCO) making the grade. The post-secondary educator earned $0.31 a share before severance and impairment charges. The market would have settled for a profit of $0.25 a share. With displaced workers looking to beef up their resumes, it's no wonder that for-profit players such as Corinthian and Apollo Group (NASDAQ:APOL) are growing nicely.

So keep watching the companies that lap expectations. Over time, doing so will be a rewarding experience for investors as the market rewards the overachievers. That's the kind of surprise we look for in the Rule Breakers newsletter service. Want in? Check out a 30-day trial subscription.

Either way, come back next Monday to learn about more stocks that blew the market away.