[ by Howard Haykin ] Regulators investigated Facebook Inc.'s IPO listing on the Nasdaq Stock Market, in search of regulatory violations.  In what might come as a disappointment to some, the examiners haven't found any evidence of industry rule violations and account for the botched offering as a technical failure, according to a person familiar with the matter. Congressional leaders, regulators and state officials had eagerly been awaiting the findings because they suspected that foul play was involved, with the disappointing price movement on the first day of trading in Facebook, as well as screw-ups in execution (or non-execution) of customers orders to led to an estimated $100 million in market maker losses. It a common belief among investors and others that, even if there are no violations in the technical exchange listing, tremendous disappointment lingers by the trading hiccups, ongoing steep share price declines, selective disclosures by underwriters, pricing of the IPO at the upper end of its price range, and the very large number of shares sold off by insiders - particularly in comparison to what the company was selling. When its own review is complete, the SEC may recommend adjusting rules for the pricing of IPOs, perhaps temporarily delaying trading of a stock after the initial price is set, the person said. The SEC is examining whether markets should wait for a more definitive signal that the opening trade has been completed and confirmed before continuous trading begins, the person said. Currently, shares start trading continuously on the open market right after an initial "print"—the price that results from the matchup of orders before trading starts.  Normally, the transition to continuous trading occurs almost simultaneously. An SEC spokesman said the agency will "continue to review issues related to the IPO" and at this point has "drawn no conclusions." Executives at Nasdaq OMX have said that after initial delays to Facebook's shares opening, a flood of canceled orders for the stock and changes to pre-existing orders interfered with its process of matching buy and sell orders to form the first trade.  It took staff about 20 minutes to resolve the matter and let the IPO proceed, during which time millions of shares of trades fell into limbo. After the initial price was set, there was a nearly 2½ hour delay in confirming trades in Facebook shares.  That in turn drove the estimated $100 million in trading losses as firms were doing business in the stock without knowing the result of their trades. FINRA is reviewing the trades and will recommend to Nasdaq which firms are entitled to compensation for their botched orders. Meanwhile, the Senate Banking Committee and House financial services committee have launched reviews of their own.  SEC officials have said their own inquiry is to ensure investor confidence in the public markets. "There are issues that we need to look at specifically with respect to Facebook," SEC Chairman Mary Schapiro said last week.   [WSJournal, 5/30/12]