News that hedgie Bill Ackman took a stake in animal drugmaker Zoetis sent the stock soaring during the last half hour of trading Tuesday.

Ackman’s Pershing Square and one of his protégés, Scott Ferguson, amassed a 10 percent stake in the company but have not yet reported the stake.

Zoetis shares jumped almost 9 percent, to close at $43.72.

The company, which focuses on animal health-care drugs, was spun out of Pfizer last year.

Pershing Square was scrambling Tuesday night to respond to the leaked news.