Clearwire started out strong in its stock market debut with an opening price of $27.25, but the stock has started to slump in recent minutes with shares trading at or just below the $25 offering price.

Craig McCaw

That could be a sign that the company priced the shares too aggressively, though there is still some time in the day to see where things end up. Clearwire raised $600 million in its IPO last night, selling 24 million shares at the top of the anticipated range. It also has reserved an additional 3.6 million shares for the underwriters.

The low point of the stock so far today came just before 9 a.m. at $24.46.

Clearwire debuts with a market capitalization of about $3.2 billion -- meaning it is valued more than RealNetworks, InfoSpace, aQuantive and F5 Networks.

More than 26 million shares have traded, which indicates that some stock flippers are trying to make a quick buck on the deal.

"I think maybe the (run-up earlier) was profit taking off the initial pop," Pali Research analyst Walter Piecyk tells The Associated Press. "I still think the stock is fairly priced for a potential 25 percent return, but it's a high risk stock, and it's possible some investors are going to require a higher return for that kind of risk."

UPDATE: Clearwire's stock ended the day at $24.62, down 1.5 percent from the initial offering price. More than 34 million shares were traded and the company finished the day with a market value of $3.1 billion. Meanwhile, Om Malik notes that Clearwire is one of the "riskiest investments out there."

UPDATE: AP reports that the Clearwire IPO landed like a "thud on Wall Street," quoting an analyst who says the company's underwriters may have been too aggressive in their pricing of the offering.