Don't settle for ordinary quarterly reports.

I take a look at three companies that beat market expectations every week, since I believe that it's the biggest factor in a stock beating the market. Leaving Wall Street's pros with stunned expressions can be a good thing. It usually means that the companies have more in the tank than analysts figured. Capital appreciation typically follows.

Let's take a look at a few companies that humbled the prognosticators over the past few trading days.

We can start with Costco (Nasdaq: COST). The warehouse club's quarterly profit climbed 16% to $0.97 a share, just ahead of the $0.95 that analysts were targeting. The outperformance isn't exactly a trend. Rival BJ's Wholesale (NYSE: BJ) came up well short in its latest quarter.

Alcoa (NYSE: AA) didn't have to wait until tomorrow -- as its old slogan goes -- to come through for its investors. The aluminum giant posted net income of $0.09 a share after backing out one-time charges, nearly twice what Wall Street was expecting.

Alcoa ran into a rough patch during the heart of the recession, but it has now come through with profitable performances in each of the past five quarters.

Finally, we have Diamond Foods (Nasdaq: DMND) shining nicely. Unlike salty snack champ PepsiCo (NYSE: PEP) -- which merely met the market's bottom-line estimate last week -- Diamond's non-GAAP adjusted quarterly net income of $0.34 a share blew past what the pros were forecasting. The maker of Kettle potato chips, Emerald nuts, and Pop Secret microwaveable popcorn was only on the hook for earnings of $0.28 a share.

It's important to keep watching the companies that surpass expectations. Over time, it will be a lucrative experience for investors as the market rewards the overachievers. That's the kind of surprise that 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.

The Fool owns shares of Costco, which is a Motley Fool Inside Value selection and a Motley Fool Stock Advisor recommendation. Motley Fool Options has recommended a diagonal call position on PepsiCo, which is a Motley Fool Income Investor recommendation. Try any of our Foolish newsletter services free for 30 days.

True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community.

Longtime Fool contributor Rick Munarriz is a fan of toppers. He does not own shares in any of the stocks in this column. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.