Investing.com - Short sellers targeting SpaceX (NASDAQ: SPCX) had accumulated an estimated $15.5 billion in paper profit through Tuesday, July 22, according to Ortex Technologies data cited by Reuters, as the stock continued to unwind its spectacular post-IPO surge.

SpaceX priced at $135 on June 11, 2026, and briefly soared to an intraday high of $225.64 on June 16 before reversing sharply.

As of the Wednesday, July 22 close, the stock was at $115.26, down 6.70% on the day, leaving it roughly 49% below that peak and about 15% under its IPO price. The short-selling campaign has escalated dramatically since the listing.

Ortex estimated that nearly 196 million SpaceX shares were sold short in late July, representing roughly 31% of the tradable float, up from approximately 40 million shares — around 5% to 7% of float, at the time of the IPO.

S3 Partners put short interest at about 185 million shares, or 29% of float, as of July 16, according to CNBC.

Perhaps more striking than the size of the short position is its trajectory. Ortex estimated the paper gains at $8.7 billion as of July 16, meaning bears nearly doubled their unrealized profits in just six days as the stock kept falling. Peter Hillerberg, co-founder of Ortex Technologies, told Reuters the pattern was unusual.

"SpaceX has been a rollercoaster for the short sellers, and it has ended up firmly in their favor," Hillerberg said. "Rather than take profits, the bears kept adding the whole way down."

Hillerberg added that about 49% of SpaceX's free float was out on loan, with Ortex believing most of that reflects active short selling.

The scale of the position creates acute two-way risk: Ortex estimates that every one-dollar move in the shares is worth more than $300 million to the short side, meaning a sharp reversal could trigger an equally violent squeeze.

"We are seeing continuous demand from short sellers building speculative positions since the IPO," Matthew Unterman, head of research at S3 Partners, told CNBC.

Posting on X, Musk warned that "the survival probability of firms who maintain a significant short position in SpaceX over time is very low."

Contributing factors behind the stock's decline include investor unease over debt-funded AI spending, and a Starship launch abort in mid-July that erased roughly $100 billion in market value.

The company's debut earnings report is set for August 4, 2026, and that date triggers the first major lock-up expiration. Starting August 6, insiders may sell up to 20% of their eligible locked-up shares, totaling as many as 911.5 million shares, per CNBC. That potential flood of new supply hangs over both longs and shorts as the biggest structural test the stock has yet faced.