HOUSTON ( TheStreet) -- Dynegy ( DYN) finished Thursday's session with gains on heavy volume on reports of a possible acquisition by NRG Energy ( NRG). Dynegy saw 44.4 million shares change hands Thursday, more than three times its three-month daily average, after Briefing.com reported market chatter about a NRG-for-Dynegy deal. Volume was greatest during the first half hour of trading, when Dynegy's stock hit an intraday high of $2.42. Shares pared gains but finished higher by 3 cents, or 1.3%, at $2.27. Briefing.com also noted that Dynegy Oct. 2009 calls were seeing greater interest than puts on the rumor. Dynegy has a 840.2 million-share float with a small short interest float of 2.6% as of Aug. 26, according to Yahoo! Finance. NRG, on the other hand, has a float of 264 million and a short interest float of 6.5%. NRG has a market cap of $7.2 billion, compared to Dynegy's $1.9 billion market cap. Investor posts on Internet message boards Thursday noted that short interest in Dynegy is considerably smaller than it was a year ago. Others argued that any takeover of Dynegy would see shares fetch a price between $4 and $5. Dynegy shares have a 52-week high of $4.30.
After rising 14% Wednesday on volume of 17.4 million, Keryx shares were lately down 11 cents, or 4.1%, to $2.58. In the first two hours of trading Thursday, more than 2.5 million shares changed hands, compared to the stock's 50-day average daily volume of 2.7 million, according to the Nasdaq's Web site. Keryx has a 44.4 million-share float, with a small short interest float of 1.6% as of Aug. 26, according to Yahoo! Finance. Investor posts on Internet message boards Thursday note that a lot of money has poured into Keryx over the last few days as the stock is up nearly 100% over the last five sessions. Other posts noted the large amount of insider buying and a small float. -- Written by Robert Holmes in New York.