Mark Cuban has been vindicated -- which is probably the very word the garrulous billionaire would use to describe a federal court's decision Friday to toss out the Securities and Exchange Commission's insider trading charges.

In a civil suit, the SEC had alleged that Cuban, owner of the Dallas Mavericks and the Landmark chain of movie theaters, among other assets, had used insider information to sell his stake in a private Internet search firm called Mama.com to avoid losses of about $750,000.

U.S. District Judge Sidney Fitzwater, however, essentially agreed with Cuban's argument that the SEC had expanded the definition of insider trading, and that he was free to legally make a trade of those shares as he had done.

Still, Fitzwater left the door open a bit for the SEC: the commission can file an amended complaint within 30 days if it can prove that Cuban "undertook a duty" not to buy or sell the Mamma.com shares using the insider information.

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