You can't stop IPOs, you can't even hope to contain them. A twist on an overused cliche, but some "SportsCenter" sayings never get too old.

The latest IPO to capture the market's attention was

WebMethods

(WEBM)

, a business-to-business software company with the hot XML label attached to it. The stock was up an amazing 170 7/16, or 486%, to 205 7/16. WebMethods was priced at $35, far above the $11 to $13 range it was originally priced.

And the strong performance of WebMethods was seeing some spillover.

PurchasePro.com

(PPRO)

was up 12 15/16, or 16%, to 96. However, other stocks that rose in anticipation of today's debut were not faring as well.

Extensity

(EXTN) - Get Report

was down 4 1/4, or 5.4%, to 74. It rallied as high as 80 earlier today after trading as low as 65 on Tuesday.

OnDisplay

(ONDS)

was up 2, or 1.8%, to 112 1/2, and

Bluestone Software

(BLSW)

was up 13/16, or 0.8%, to 98.

TheStreet.com Internet Sector

index was down 14.63, or 1.25%, to 1162.87.

TheStreet.com New Tech 30 was down 6.77, or 0.98%, to 684.42.

Randall Roth, analyst with the

Renaissance Capital IPO Fund

, said the IPO market is spreading into new areas with new buzzwords like XML, but one thing should be a constant for investors: "Know the companies you're investing in." Roth said companies can try to position themselves in whatever is the hot sector of the day, but investors need to do a little research before jumping headfirst into the volatile IPO market.

Roth continues to recommend that individual investors wait at least a week before they get into IPOs, especially with a hot stock like WebMethods, as time may give you a better entry point if the stock dips.

"Finding a suitable entry point is hard. Even the pros don't know when to get in," Roth said. "See how the trading develops and whether there is a pattern, any news or any surprises."