Activist investor famous for his high-profile battle with Herbalife claims short was 'most philanthropic investment I have ever made.'» Read More
As CEO of his own soon-to-be public company, Bill Ackman will use a dual share-class structure that has been considered unfriendly to investors.
U.S. stocks closed down on Friday, breaking five weeks of consecutive gains as investors awaited the Federal Reserve's announcement next Wednesday.
Take a look at some of Friday's midday movers:
William Ackman criticized Allergan's board of directors, urging them to "wake up" and at least listen to potential purchaser Valeant Pharmaceuticals.
Securities regulators are looking into the joint bid by Valeant Pharmaceuticals and activist investor Bill Ackman for Allergan, Dow Jones reported.
A lawsuit by Allergan says the unusual arrangement by Valeant Pharmaceuticals and activist investor Bill Ackman amounts to insider trading.
Allergan sued Valeant Pharmaceuticals and Pershing Square Capital, alleging both acted inappropriately in their hostile $53 billion bid.
A Republican congressman will pressure the Securities and Exchange Commission for reforms after Bill Ackman's efforts to take over Allergan.
As Bill Ackman said Herbalife needs to be shut down, the stock soared. Here's how much he may have lost in options alone.
Analyst Tim Ramey said assertions made by Bill Ackman during Tuesday's presentation are untrue, and Ackman is correcting the record.
Bill Ackman fired his latest shot at Herbalife Tuesday, but the company's stock mostly rose during the investor's presentation.
Bill Ackman, head of Pershing Square Capital Management, said his firm's presentation of a Herbalife investigation will "expose incredible fraud."
Herbalife is ramping up its rhetoric against arch-nemesis Bill Ackman.
John Paulson, founder of hedge fund firm Paulson & Co., said corporate M&A activity "will continue for the foreseeable future."
Allergan told its stockholders not to respond to Pershing Square Capital Management's proposal to replace a majority of the board.
The S&P 500 may have rallied 6 percent during the first half of the year, but the average hedge fund appears to have trailed that substantially.
Allergan advised investors not to sell their shares to Valeant, which launched a hostile takeover offer for the Botox maker last week.
Valeant said it plans to launch an exchange offer to Allergan shareholders this week, soliciting proxies to call for a meeting to discuss its offer.
Allergan's board of directors announced on Tuesday that it has unanimously rejected a revised, unsolicited buyout offer from Valeant Pharmaceuticals.
Now that they've made-up, Bill Ackman tells CNBC he's trying to get Carl Icahn to sell Herbalife.