Uber short-sellers made $270 million in just 2 days as the stock plunged to record lows

• Uber short-sellers recorded $270 million in mark-to-market profits in two days, according to data from IHS Markit.
• The returns were driven by Uber falling to record lows after it reported disappointing third-quarter earnings and its post-IPO lockup expired.
• Uber shorts have been slowly adding to their positions since August, according to Sam Pierson, IHS Markit's director of finance securities.
• Watch Uber trade live on Markets Insider.

Uber short-sellers are seeing solid returns as the stock falls to record lows.

Traders who have bet against the ride-hailing giant recorded $270 million in mark-to-market profits in two days, which is about 43% of their year-to-date returns of $640 million, according to data from IHS Markit.

Here's the breakdown. On Tuesday, short-sellers netted $200 million when Uber shares fell 9.85% to a record low after the company reported disappointing earnings results. On Wednesday, short-sellers logged an additional $70 million in early trading when Uber's post-initial public offering lockup period expired, sending shares down as much as 8.7%.

Uber has struggled to win over investors since its May IPO, largely due to the company's massive quarterly losses and forecast that it won't turn a profit until full-year 2021. On Wednesday, the company's market valuation at the stock price's intraday low was $43.6 billion, its lowest since 2015, when the company was privately held.

The falling stock price has benefited short-sellers, who make a profit when share prices decline. There are currently about 74 million Uber shares on loan, which means a $2 billion short position against the company, according to Sam Pierson, Markit's director of securities finance.

To realize the gains Uber short-sellers have seen, they would have to cover their trades, or buy back the shares they borrowed to short. So far, there hasn't been much evidence that short-sellers are exiting the trade, according to Pierson.

In fact, he's seen the opposite. "There's just been a kind of slow steady increase in the shares on loan, the short interest, up to this point," Pierson told Markets Insider in an interview.

Uber is down roughly 42% year-to-date.