Martin Shkreli has surely made a lot of enemies on Wall Street. His arrest by federal agents on Thursday could add to that list, burning a lot of investors bullish on KaloBios Pharmaceuticals Inc., just a month after he squeezed out those who were bearish.

Complicating matters, those eager to dump their KaloBios shares will have to wait, as they were halted for trading indefinitely, until the Nasdaq gets information it has requested amid his arrest on charges of securities fraud.

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The stock’s US:KBIO last trade ahead of the halt was at $11.03 before the market opened on Thursday, which was down $12.87, or 53%, from Wednesday’s closing price of $23.59.

FactSet

KaloBios shares became a hot topic last month, when the stock rocketed after the drugmaker said Shkreli’s investor group had acquired more than a 50% stake in the company. That prompted one short seller to make a plea on GoFundMe to help cover losses of over $100,000 incurred as his bearish bet went bad.

He wasn’t alone. Short interest on the stock through mid November was 60 times higher than it was three months before, according to FactSet data. As short sellers scrambled to cover their bearish bets, the stock shot up to close at $39.50 on Nov. 23, an 1,800% increase in just three days.

Shkreli made matters worse for bears, by refusing to lend any more shares to those looking to short sell them. To short a stock, one must first borrow the stock, then sell it, with the hope of buying it back at a lower price before returning the stock to the lender.

Investors who bought the stock during that rally, are now facing large losses, once the trading halt is lifted.

Some might call it poetic justice, that Shkreli is among the investors being hurt by his own arrest. When he woke up Thursday, the 2,075,200 shares of KaloBios he owns was worth $26.7 million less than when he went to sleep. However, the pre-halt price was still more than six times the closing price on Nov. 16 of $1.72, which was the day Shkreli acquired his KaloBios stake, according to regulatory filings. View Shkreli’s timeline:

Shkreli had already made a lot of enemies from Main Street to the Beltway before the KaloBios saga began. He is also the CEO of Turing Pharmaceuticals, which famously jacked up the price of a drug it had recently acquired by more than 5,000%.