But for every optimist backing Musk’s bid to establish a human colony on Mars is an investor on earth wondering if the plan will ever take off. Burry, in typical form, was open in asking that question.

In a Substack post, the analyst best known for predicting the housing crash before the 2008 financial crisis said he had reviewed a number of trading options for betting against Musk’s company.

“I am not involved with SpaceX now. Neither short nor, ahem, long,” Burry wrote Tuesday, per CNBC. Put options on the shorter end—expiring in June 2027, for example—cost roughly $13 with the stock trading at around $212, Burry reported. A put ending December 2026 was priced at around $6.75, he added.

Burry was “tempted by that one. But no thank you,” he wrote of the short option.

He isn’t sold on the eye-watering valuation of Musk’s latest venture, which he described as “fundamentally a small space company, a niche telecom, a bedeviled social media company, and a CoreWeave-light.”

Investors did get a chance to peek at the company’s financials ahead of its IPO in the form of an S-1 filing, which revealed that while revenue is up, so too are losses. As Fortune previously reported, Space Exploration Technologies Corp. (SpaceX) is growing at a steady clip—full-year revenue of $18.7 billion in 2025 increased roughly 33% from $14.1 billion in 2024—but its losses are also accelerating.

As of March 31, SpaceX has racked up an “accumulated deficit” of $41.3 billion, with a $4.27 billion net loss in Q1 of this year, compared with $528 million in the year-ago quarter.

Fortune also reported on David Trainer’s analysis from research firm New Constructs, which revealed that nearly 80% of the capital expected to be generated by the IPO was spoken for. From the S-1 filing, Trainer discovered that $62.8 billion (or 78%) of the forecasted $80 billion in capital was already dedicated to insiders and vendors. Specifically, SpaceX pledged to pay more than three-quarters of the proceeds to third parties, Valor Equity Partners (a large shareholder), Musk X Corp., and xAI investors for repayment of debt, and EchoStar for “the Spectrum Acquisition Closing.”

A bet against Musk

Musk is a notoriously busy man—variously running EV manufacturer Tesla, launching SpaceX onto the market, helping oversee the running of social media company X, and managing a controversial stint in the Trump administration last year—but even then, he finds time to push back at those who move against him.

His feud with Microsoft cofounder Bill Gates is particularly well-known, and last year he revived a years-old argument with claims that Gates still held a “crazy” short position against Tesla.

“If Gates hasn’t fully closed out the crazy short position he has held against Tesla for ~8 years, he had better do so soon,” said Musk in a November post.

The bad blood began in 2022 when Gates reportedly shorted, or bet against, Tesla’s stock to the tune of $500 million, earning him a text from Musk and “super mean” behavior, Gates said in a later interview with Musk biographer Walter Isaacson. At the time, Musk asked Gates if he had taken a short position, which he confirmed, but added he wanted to work with the Tesla CEO on philanthropy.

Musk reportedly responded: “Sorry, I cannot take your philanthropy on climate change seriously when you have a massive short position against Tesla, the company doing the most to solve climate change.”

Burry may, at some point, feel compelled to bet against SpaceX—but Musk hasn’t taken such slights lightly in the past.