Valeant's +40% Single-Day Decline Equates To Over $666 Million Loss For Bill Ackman

Those hit hard by Valeant Pharmaceuticals Intl Inc VRX’s 45 percent post-earnings selloff can at least take comfort in one fact: they haven’t lost as much money as Bill Ackman has.

In fact, based on his most recent SEC filing, Ackman’s Pershing Square Capital is down $666.7 million on its Valeant shares alone in Tuesday’s session.

Unfortunately for Ackman, the pain doesn’t stop there. Pershing also holds more than 9 million shares of unexercised Valeant options.

Conservative estimates of how much Ackman has lost on Valeant since he first started buying the stock put him down more than $2.6 billion overall on the position following today’s drop.

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In fact, things have gotten so bad for Ackman, that speculation that margin calls are forcing Pershing to liquidate its top holdings have driven down shares of Ackman’s other favorite stocks in Tuesday’s session. Air Products & Chemicals, Inc. APD is down 1.6 percent, Canadian Pacific Railway Limited (USA) CP is down 3.2 percent and Mondelez International Inc MDLZ is down 1.4 percent.

Despite the huge losses, Ackman has stuck to his guns on Valeant thus far, sendinig out an email to investors on Tuesday explaining that the stock is worth "multiples" of current prices.

Disclosure: the author holds no position in the stocks mentioned.