Beam, the maker of Jim Beam, has agreed to be acquired by Japanese brewing and distillery company Suntory for $13.62 billion.
Shares of Beam were last trading up more than 25% in the pre-market at about $84.30 per share. The stock closed at $66.48 per share on Friday.
This is a huge score for Bill Ackman, who runs Pershing Square Capital.
As of September 30, 2013 Pershing Square held 20,818,545, or 12.77%, of Beam shares, 13F data compiled by Bloomberg shows.
Assuming he hasn't pared back his stake, Ackman has made about $371,016,525 on this position since Friday.
Dealbook's Michael J. De La Merced points out that Ackman was the one who pushed for Beam to split from Fortune Brands a few years ago. Since Beam became a separate company in October 2011, shares have risen more nearly 24%.
A 13F filing for the quarter ended December 31, 2011, shows that Ackman has held the same amount (20,818,545 shares) of shares in Beam. That means he has made around $688,499,336 on this position since that time.