Sadly, there's no such thing as an ultimate buy signal when it comes to investing in stocks. Identifying companies with the wind at their backs takes time, patience, and a good dose of due diligence.

There is, however, an easy way to increase your odds of finding the stocks that will beat the market. At Motley Fool CAPS, the Fool's investing community of more than 135,000 members, we've found that our "five-star portfolio" is up 15.31% between January 2007 and April 2009, compared with a loss of 40.6% for the S&P 500.

To fully capture the upside potential of those highly rated stocks, it makes sense to identify them just as soon as they are upgraded to four- and five-star status. Fortunately, our CAPS screener now makes it possible to do this. Below, for example, is a list of companies that have been upgraded to four-star status from three stars just yesterday. These stock ideas are only a starting point, of course. Be sure to join us on CAPS to dig in even further.

Company

All-Stars Saying Outperform

Gastar Exploration (USA) (AMEX:GST)

171 of 175

Inverness Medical Innovations (NYSE:IMA)

207 of 227

China Telecom (ADR) (NYSE:CHA)

532 of 556

National Health Investors (NYSE:NHI)

94 of 103

American Safety Insurance Holdings (NYSE:ASI)

102 of 108

IntercontinentalExchange (NYSE:ICE)

786 of 835

Western Digital (NYSE:WDC)

882 of 931

Data from Motley Fool CAPS, Aug. 18, 2009.

Come and join us on CAPS, absolutely free, to learn more about these and countless other interesting stock ideas.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.