The Lehman Brothers bears took a bath when the market rallied on the news that the company had raised $4 billion to shore up its capital position. A lot of put buyers and short sellers were hit hard. Lehman Brothers now thinks the heaviest shorting came from hedge funds that illegally conspired to drive down its stock price. Lehman has forwarded information on the matter to the SEC. According to the Financial Times, executives believe a coordinated effort to attack its stock began on March 16, the day Bear's sale to JPMorgan was announced. Lehman's stock fell nearly 50 percent on that day. Short interest hit a record 43 million shares. A lot of those guys, subsequently, were forced to cover, which aided a huge rally. Such allegations will be hard to prove but there maybe some truth to them. Still, some say Lehman can't blame the shorts entirely.  

For more:
- here's the Financial Times article

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