Momentum investors love to back companies with the wind in their sails. Contrarian investors typically pick up the cigar butts the market has tossed aside. So what do you call investors who turn against winners? Sourpusses? Shorts?

Over on Motley Fool CAPS, we sometimes call them the savviest investors around. When one of our All-Star players -- those whose stock-picking prowess places them in at least the 80th percentile of our community -- sours on a top-rated stock, perhaps we should take notice. Perhaps the player's found a chink in that highflier's armor, or a question mark in its financial footnotes. Or maybe it's just a hunch. That's why these tables aren't lists of stocks to buy or sell -- just starting points for further research.

Here's a list of stocks that some All-Stars have recently spurned:

Company

CAPS Rating (5 Max)

1-Year Return

CAPS All-Star

Player Rating

Suntech Power (NYSE: STP)

*****

24.3%

kingrimreaper

91.07

Philip Morris (NYSE: PM)

*****

N/A

otsc257

93.64

Quest Capital (AMEX: QCC)

****

(23.8%)

goldminingXpert

99.00

Valero (NYSE: VLO)

*****

(28.5%)

Michaelshawn

95.26

Sigma Designs (Nasdaq: SIGM)

*****

(39.8%)

bobbyd16

95.97

N/A = not applicable.

Considering that, on average, 96% of all the investors rating these companies think they will outperform the market, what might have turned some of CAPS top players against these stocks?

An attractive patina
Had black-and-white television been invented today, no doubt it would have some important-sounding moniker attached to it. Alas, it was invented in the boring past, so it's just called "television." Today, however, we have IPTV, which is digital television delivered via the Internet and offering us movies on demand, Web access, and even VoIP.

To get that high-tech broadcast to our TVs, we need set-top boxes that can receive the programming. Sigma Designs is one of the companies making the chips that power those boxes. While an earnings miss set the stock back recently, could there be other misses poised to disconnect the company?

Analysts think the company's $350 million revenue guidance is too high for the coming quarter and have begun downgrading the stock. Moreover, one analyst says Broadcom (Nasdaq: BRCM) has won the next-generation IPTV set-top box for Motorola (NYSE: MOT). That could set the stage for a major loss of market share.

It also looks bleak on the Blu-ray side of things. The chip designer currently holds a large share of the next-gen DVD player market according to one analyst. That's key when you consider that, as the sole standard format, Blu-ray player sales ought to begin surging. Yet there, too, analysts are looking for share losses because of pricing issues.

On the other hand, CAPS investors like DutDut310 see the Blu-ray phenomenon as a key to growth. While there are concerns about declining margins in a highly competitive space, industry trends should ease worries, says this investor:

Imagine in the (very near) future when Blu-Ray players have [taken] the place of the DVD [and] the internet tv [has taken] the place of traditional television as consumers turn more to on demand television rather than hour by hour schedules. I believe this company will be the leading supplier of the software that run these portable media devices, presenting a huge opportunity for us with the company trading ... with a P/E ratio at its LOWEST in 5 years. (8.77 on 4/2/08).

Make lemonade from lemons
We've seen the direction some investors have indicated they believe these companies are heading, but the Motley Fool CAPS community is more than what the pros think, even if they're All-Stars. It's where we invite you to share your thoughts and insights and add your voice to the debate. We're eagerly waiting!

Sigma Designs and Suntech Power are Rule Breakers recommendations. You'll end up loathing yourself if you don't take advantage of the 30-day free trial offer available for any of the Fool's investment services.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings. The Motley Fool has a disclosure policy.