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 back 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 to a loss of 40.6% for the S&P 500.

In order to fully capture the upside potential of those five-star stocks, it makes sense to identify them just as soon as they achieve 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 five-star status from four 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

Weatherford International Ltd. (NYSE:WFT)

777 of 800

Webzen, Inc. (ADR) (NASDAQ:WZEN)

198 of 213

PartnerRe Ltd. (NYSE:PRE)

109 of 117

AmeriGas Partners, L.P. (NYSE:APU)

153 of 163

Public Service Enterprise Group, Inc. (NYSE:PEG)

261 of 273

Data from Motley Fool CAPS, July 20, 2009

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