Prediction Markets Favor Anthropic to Challenge SpaceX for 2026's Largest IPO

SpaceX raised $85.7 billion in its IPO this year, nearly triple the previous historical record. However, this crown may soon be claimed by another. According to the latest data from prediction markets, AI startup Anthropic is poised to become the largest IPO of 2026.

Trading data from platforms such as Kalshi and Polymarket show investors believe Anthropic is highly likely to surpass SpaceX. As of August 26, traders on Polymarket assessed the probability of Anthropic exceeding SpaceX at 63%. Just four weeks earlier, traders had considered this nearly impossible, indicating a dramatic shift in sentiment within a short period.

SpaceX priced its shares at $135 per share at listing, issuing approximately 555.6 million shares for a valuation of $1.77 trillion. In contrast, some market observers estimate Anthropic’s target valuation for its IPO could reach as high as $2 trillion.

The reason this AI startup, developer of the Claude large language model, has ignited market enthusiasm in just one month lies in its astonishing revenue growth. According to Bloomberg, Anthropic’s annualized revenue run rate surged from approximately $9 billion at the end of 2025 to $65 billion by the end of July 2026.

Moreover, Anthropic counts high-profile long-term subscribers such as Meta (META-US) and Microsoft (MSFT-US), and has received strong investments from Amazon (AMZN-US) and Alphabet (GOOGL-US), holding stakes of approximately 21% and 14%, respectively.

However, columnist Sean Williams has issued a warning against this frenzy. Williams points out that justifying such astronomical valuations remains the biggest challenge both companies face.

SpaceX’s price-to-sales ratio (P/S ratio) at listing exceeded 100 times its 2025 revenue. Williams emphasizes that historically, no company at the forefront of disruptive technology has sustained a P/S ratio above 30 times over the long term. Even using the latest annualized revenue figures, Anthropic clearly sits within historical bubble territory.

Additionally, Williams notes that over the past 30 years, no revolutionary technology has avoided an early bubble burst, as investors consistently overestimate the speed of new technology adoption and optimization. While spending on AI infrastructure is currently extremely high, it may still take years for enterprises to truly optimize and apply AI solutions effectively.

Williams further cites data from Truist Financial showing that, over the past 14 years, the top 30 most hyped tech IPOs experienced an average maximum drawdown of 55% in their first year of trading. SpaceX, from its post-IPO peak to date, has already seen a maximum decline of 54%.

Finally, Williams advises that despite prediction markets anticipating Anthropic will rewrite Wall Street history, retail investors should maintain distance at this stage and avoid blindly chasing the trend.