"The bigger they are, the harder they fall." It's the worst nightmare of every investor in today's market -- buying a hot stock just before it takes a nosedive.

Every day, Nasdaq.com publishes a list of stocks whose shares have just hit new 52-week highs. And every day, investors read the list and tremble -- some with greed, others with terror. In our Motley Fool CAPS investing community, these top stocks usually enjoy favorable ratings, since everyone loves a winner. But what should you do when some of CAPS' smartest investors pan one of these hot stocks?

For starters, consider using the "52-week high" list as a starting point for further research. Stocks can rise for many reasons, but a little help from Motley Fool CAPS can make it easier to figure out how worthy those reasons are. Let's see what the more than 83,000 stock gurus (and counting) in CAPS have to say about the list's latest contenders:

One Year Ago Today

Currently Fetching

CAPS Rating (out of 5)

Urban Outfitters  (Nasdaq: URBN)

$24.90

$30.31

***

CNX Gas (NYSE: CXG)

$24.95

$37.05

***

Vnus Medical  (Nasdaq: VNUS)

$9.48

$16.68

**

Sport Supply Group (AMEX: RBI)

$9.18

$11.88

**

Alphatec Holdings (Nasdaq: ATEC)

$4.13

$5.87

*

Companies are selected from the "NASDAQ 52 Week High" list published on Nasdaq.com on the Saturday following close of trading last week. One year ago and current pricing provided by Yahoo! Finance as of that date. CAPS ratings from Motley Fool CAPS.

Everybody loves a winner
When stocks soar on the wings of success, bears usually become rare. Not so this week, as we find CAPS investors expressing serious skepticism over the week's winners. Not a single stock on today's list enjoys above-average ratings, and one of them gets the lowest rating we assign on CAPS -- a single, solitary star. The single, solitary stock so tagged: Spinal-surgery implants maker Alphatec Holdings.

Funny. I thought health care was one of the few sectors that's supposed to hold up well in a recession. I mean, if you get sick, you get sick -- regardless of the health of the economy, you're going to find a way to pay to get better, right? To find out what's wrong with that theory, let's take a look at ...

The bear case against Alphatec Holdings
And now let's stop. Because as we quickly learn from a glance at Alphatec's CAPS page, nearly half the investors who've looked at the stock think it's going to underperform the market ... but not a man jack among them has bothered to tell us why.

Build-a-bear, anyone?
But perhaps you can? Tell us why we might not want to own Alphatec, that is. It's really not that hard to write a CAPS pitch, you know, and if you write anything even halfway decent, I can practically guarantee that you'll soon be featured as our "Top Bear Pitch" on the company. Here, let me get you started:

"I have a bone to pick with Alphatec. Rival Orthofix (Nasdaq: OFIX) manages to earn a profit fixing spinal injuries. Zimmer (NYSE: ZMH) is swimming in free cash flow. Yet Alphatec is burning cash, and unprofitable since the day it came public on June 1, 2006..." And you can take it from there.

Or not. If you're actually bullish on Alphatec, trust that we want to hear from you, too.

Motley Fool CAPS: It's fun, it's free, and it just might make you famous.

Fool contributor Rich Smith does not own shares of any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 521 out of more than 83,000 players. The Fool has a disclosure policy.