Facebook shares closed higher for the first time in four days of trading Wednesday, reversing a jolting, three-day tumble after the social network made its market debut on Friday.

Stocks ended the day up 3 percent to $32, where the price had hovered for much of Wednesday. The company had priced its initial public offering at $38 a share, and the price had been falling ever since.

The gains were offset by news that several investors were suing the company and some of its underwriters for their handling of the IPO. And analysts and lawmakers moved to unravel what happened before and after the shares hit the Nasdaq market on Friday. Facebook’s debut was delayed until 11:30 a.m., after Nasdaq’s systems were overwhelmed with orders in the first few minutes after the stock posted on the exchange. On Wednesday afternoon the New York Stock Exchange rejected reports that it had reached out to Facebook to discuss switching the company’s Nasdaq listing.

“There have been no discussions with Facebook regarding switching their listing in light of the events of last week. Nor do we think a a discussion along those lines would be appropriate at this time,” said NYSEEuronext spokesman Eric Ryan.

California firm — Robbins Geller Rudman & Dowd — released more information Wednesday on a class-action suit it filed in the U.S. District Court for the Southern District of New York. The lawsuit alleges that Facebook used “false and misleading” language in its S-1 filings regarding its revenue growth.

The banks underwriting Facebook’s IPO have also drawn the gaze of lawmakers and regulators. The Massachusetts Secretary of the Commonwealth has filed a subpoena against Morgan Stanley-- the lead underwriter for Facebook’s IPO-- after reports that an analyst there cut his revenue forecast after the company’s May 9 filing, which indicated that it was expecting less revenue because of a shift to mobile users.

The suit drew the attention of the Senate banking committee. In a statement Wednesday, Sen. Tim Johnson (D-S.D.), the committee chairman said: “I have instructed my staff to conduct due diligence regarding issues raised in the news about Facebook’s IPO. My Banking Committee staff is coordinating bipartisan staff briefings with Facebook, regulators and other stakeholders.”

Johnson said that when the staff reports back “I will determine if a Senate Banking Committee hearing is necessary.”

Morgan Stanley declined to comment on any regulatory inquiries Wednesday but said the bank complied with regulations in revising its revenue forecast for Facebook.

“Morgan Stanley followed the same procedures for the Facebook offering that it follows for all IPOs. These procedures are in compliance with all applicable regulations,” the firm said in a statement to The Washington Post. The bank said that a copy of the amended S-1 statement was forwarded to all Morgan Stanley “institutional and retail investors.”

Anthony Michael Sabino, a professor at John’s University’s Peter J. Tobin College of Business said that the incident is a black eye for Morgan Stanley and certainly a hit to the firm’s reputation. He added that the accusation, “bears close scrutiny” and could be troublesome if only a small circle of investors were privy to the revenue information.

“This is just the first wave of government investigations and investor lawsuits, undoubtedly with more to come,” Sabino said. But he found it unlikely that Facebook was actually guilty of securities fraud.

“Let’s sort out a few things first,” he said. “Securities fraud? Highly unlikely. The objective is to make money for everybody, and it would be pointless to try to defraud anyone here on an IPO of such staggering proportions. Bungling? Could very well be.”

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