SAN DIEGO (

TheStreet

) --

Cardium Therapeutics

(CXM)

shares fell sharply Thursday on heavy volume after the company announced a $6 million registered direct offering of common stock.

Cardium Therapeutics said the securities in the offering include an estimated 4.61 million shares of Cardium common stock at a price of $1.30 and warrants to purchase up to 3 million shares of common stock at an exercise price of $1.40.

News of the $6 million direct offering comes shortly after Cardium on Thursday announced the publication of positive clinical findings of Excellarate, its candidate for the potential treatment of non-healing diabetic foot ulcers.

Shares of Cardium Therapeutics were dropping by 20 cents, or 14.3%, to $1.20, not far from the intraday low of $1.19. More than 5 million shares changed hands by 11 a.m. EDT Thursday, compared to the stock's three-month average daily volume of 431,000, according to the Yahoo! Finance.

Cardium has a 39.6 million-share float with a short interest float of 1.9% as of Sept. 25, according to Yahoo! Finance. More than 15% of the company's shares are held by insiders with another 6.9% owned by institutions.

Investor posts on Internet message boards suggested that the news of the direct offering may have been leaked Wednesday, as the stock tumbled by 28.6% to $1.40, the exercise price of the warrants, on volume that topped 11.5 million shares. Others argued that the high volume of shares while the stock was in a freefall was a sign of market manipulation, although it offered a more attractive entry point.

Read more about today's high-volume stocks in earlier "Pump Up the Volume" posts

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-- Written by Robert Holmes in New York

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