Just like opening day at the ballpark, investing in new IPOs holds the potential for shining promise and crushing disappointment. If you simply can't bear to just cheer on your favorites from the sidelines, at least be careful about investing in this league. Many new issues swing for the fences during their first trading days, only to slump once marketing hype has given way to mundane earnings reports.

Don't commit an error by stocking your entire portfolio with rookies. Allocate just a small percentage of your risk capital to IPOs. Scout your potential phenoms carefully, and be choosy about composing your own rotisserie league. Investing with an eye for a season extending long beyond opening day will reward you with quality players capable of staying in the game. With that in mind, we offer our Foolish scouting report of the latest IPOs.

Last week's games
Several games took place last week, ranked below according to how the players performed.

Winner: Allied World Assurance (NYSE:AWH)

  • Industry: Property and casualty insurance, reinsurance
  • Deal terms: $34 per share, at the low end of its range; 8.8 million shares
  • Lead manager: Goldman Sachs
  • Opening day: July 12 -- opened at $34.75 and closed at $34.25; 1% gain
  • Bleacher banter: richest IPO for a domestic insurance company in over two years; Goldman plays multiple positions as underwriter and major shareholder of company's private equity funds

Runner-up: Valero GP Holdings (NYSE:VEH)

  • Industry: Oil and gas
  • Deal terms: $22 per share, at the low end of its projected range; 17.25 million shares
  • Lead underwriter: Lehman Brothers
  • Opening day: July 14 -- opened flat and closed at $22.03; 0.1% gain
  • Bleacher banter: respectable return in a tough week for the market

Loser: Cowen Group (NASDAQ:COWN)

  • Industry: Investment banking
  • Deal terms: $16 per share, below its $19-$21 per share forecast; 11.2 million shares
  • Lead managers: Cowen & Company, Credit Suisse, and Merrill Lynch
  • Opening day: July 12 -- opened flat and closed at $15.88; 0.7% loss
  • Bleacher banter: A turbulent market resulting in a 120 decline in the Dow did nothing to help the deal. Some pundits cited the company's concentration on the tech sector and brokerage and underwriting as opposed to pure advisory services as obstacles in a market closely scrutinizing smaller players.

On deck
Only one major IPO is slated for the coming week:

NewPage Holding

  • Proposed ticker: NYSE: NWP
  • Industry: Coated paper manufacturer
  • Proposed deal terms: $14-$16 per share; 20 million shares
  • Lead manager: Goldman Sachs, UBS, Citigroup

Game of the week
You should watch NewPage, as it's the only game being played on this week's slower-than-usual summer schedule. It's an "old economy" company that operates four integrated pulp and paper mills in Kentucky, Maine, Maryland, and Michigan. Last year, the company reported a pro forma net loss of $32 million based on pro forma net sales of $1.86 billion. Don't expect any immediate home runs here.

If you still can't satisfy your IPO obsession, tune into what's happening with Russian state-owned oil company Rosneft. On Friday, the firm priced its shares at $7.55, raising $10.4 billion and making it the world's fifth-largest IPO and the largest ever for a Russian company. Shares are garnering strong demand from international oil companies and are expected to begin trading in London on Wednesday, despite Russian rival Yukos attempting to block the deal legally on its claim that Rosneft stole its assets through government-enforced action.

Warming up in the bullpen
Unless otherwise noted, the timing of the following deals has not yet been determined.

GeoMet, a provider of temporary physician staffing services, announced the terms of its proposed offering to include a price range of $13-$15 per share for 6 million shares. The lead manager is Banc of America.

CHG Health Care Services, a provider of temporary physician staffing services, announced the terms of its proposed offering to include a price range of $15-$17 per share for 4.925 million shares. Lead managers are Citigroup and Lehman, and the deal is expected to price the week of July 24.

Security Capital Assurance, a Bermuda-based holding company for the financial guaranty business of XL Capital, announced the terms of its proposed offering to include a price range of $21-$23 per share for 22.45 million shares. Lead managers are Goldman Sachs, JPMorgan Chase, and Merrill Lynch.

Alien Technologies, a manufacturer of radio frequency identification products, announced the terms of its proposed offering to include a price range of $10-$12 per share for 9 million shares. The lead manager is Bear Stearns.

Crystal River Capital, a real estate investment trust, announced the terms of its proposed offering to include a price range of $26-$29 per share for 9.1 million shares. The lead managers are Deutsche Bank and Wachovia Securities.

Minor-league developments
Get ready, get set . not yet! The latest filings announced last week include:

Penn Virginia Corp.

  • Proposed ticker: NYSE: PVG
  • Industry: Coal and natural gas
  • Proposed deal terms: as much as 6 million common units
  • Lead managers: Lehman Brothers and UBS
  • Filed: July 11

Hertz Global Holdings

  • Proposed ticker: NYSE: HTZ
  • Industry: Car and equipment rental
  • Proposed deal terms: Not yet determined
  • Lead managers: Goldman Sachs, Lehman, Merrill Lynch, Deutsche Bank, JPMorgan Chase
  • Filed: July 14

Metabolix

  • Proposed ticker: Nasdaq: MBLX
  • Industry: Biotech
  • Proposed deal terms: Not yet determined
  • Lead managers: Piper Jaffray
  • Filed: July 14

Logan's Roadhouse

  • Proposed ticker: Nasdaq: LGNS
  • Industry: Restaurants
  • Proposed deal terms: Not yet determined
  • Lead managers: Wachovia Securities
  • Filed: July 14

Disabled list
These former wannabes announced their withdrawals of planned offerings: Berkline/Benchcraft Holdings and Wintegra Inc., which cited unfavorable market conditions.

Current champions
Meet our current 2006 champs. Among companies that went public this calendar year, these firms' percentage returns from their offer prices to last week's closing price rank them as the top five players:

Company

Ticker

Return

Description

IPO Date

Chipotle Mexican Grill

(NYSE:CMG)

+146%

Mexican restaurant operator

1/25/06

Novacea

(NASDAQ:NOVC)

+58.6%

Biotech

5/9/06

H&E Equipment

(NASDAQ:HEES)

+54.2%

Industrial equipment service provider

1/30/06

FortuNet

(NASDAQ:FNET)

+53.3%

Electronic gaming manufacturer

1/30/06

Aeroportuario del Pacifico

(NYSE:PAC)

+46%

Mexican airport facility operator

2/23/06



Current benchwarmers
Now, meet our current 2006 benchwarmers. (That's nicer to say than "losers," isn't it?) Among companies that went public this calendar year, these firms' percentage returns from their offer prices to last week's closing price rank them as the bottom five players:

Company

Ticker

Return

Description

IPO Date

Vonage

(NASDAQ:VG)

(60.2%)

Traffic information provider

5/23/06

Traffic.com

(NYSE:TRFC)

(57.5%)

Broadband telephone services

1/24/06

IncrediMail

(NASDAQ:MAIL)

(44.7%)

Email software manufacturer

1/30/06

Iomai

(NASDAQ:IOMI)

(42.7%)

Biopharmaceutical company

1/31/06

Himax Technologies

(NASDAQ:HIMX)

(40.7%)

Semiconductor manufacturer

3/30/06



Groupies and fan clubs
If you don't want to declare your loyalties for specific players but still want to enjoy the action, consider subscribing to an IPO-focused mutual fund or exchange-traded fund. Of course, do your scouting homework here, too, and make sure you read their prospectuses before buying season tickets.

Last week, First Trust IPOX 100 (AMEX:FPX), an ETF, and the IPO Plus Aftermarket (FUND:IPOSX), a mutual fund, lost 3.9% and 5.2%, respectively. There were no winners in the overall market, either. The Nasdaq fell 4.4%, and the Russell 2000 slipped 4%.

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Fool contributor S.J. Caplan roots for the Cleveland Indians when her husband is watching, and for the Boston Red Sox when he leaves the room. She holds no financial position in any firms or funds mentioned here. The Fool has a disclosure policy.