Will SpaceX have the highest IPO Market Cap 2026?

As of September 1, 2026, Polymarket prices “Will SpaceX have the highest IPO Market Cap 2026?” at 46% YES with $881K traded. No tracked wallet holds a position on this market, so there is no verdict.

Prediction markets put the probability at 39%: Will SpaceX have the highest IPO Market Cap 2026. Currently, markets are divided (39% YES, 61% NO). SpaceX has since rallied back to $146 a share, giving the company a market cap of $1.93 trillion.

What’s Happening

Traders on Polymarket have priced the likelihood that SpaceX will have the highest IPO market cap in 2026 at **39% YES** versus **61% NO**, a dramatic reversal from just two weeks ago when the Elon Musk-led company commanded odds as high as **90%**. The shift follows a surge in confidence for rival Anthropic, which now leads the same proposition with **58% odds** after Bloomberg reported the AI startup is accelerating toward a potential fourth-quarter market debut. SpaceX, which went public in June 2026 at **$135 per share** and peaked at **$202 on June 16**, has since seen its stock retreat to **$146**, giving the company a market capitalization of **$1.93 trillion** — still the largest among recent tech listings but no longer viewed as untouchable. [Forbes, Aug 26]

The narrowing gap between the two contenders reflects a fundamental reassessment of SpaceX’s post-IPO valuation trajectory. Following its **February 2026 merger with xAI**, SpaceX operates as three distinct businesses: Falcon 9 launch services commanding roughly **90% of global commercial launch market share**, Starlink targeting **100 million subscribers and $140 billion in revenue by 2030**, and the xAI subsidiary projected to represent **70% of the business by that same year**. However, the company’s stock has fallen **30% from its post-IPO high** after announcing a deal to acquire Cursor, which triggered a selloff that erased more than **$1 trillion in market cap** at the trough. Anthropic, by contrast, is currently valued at approximately **$1 trillion** in private markets, compared to **$894 billion for OpenAI**, with revenue growth accelerating into its expected listing. [Motley Fool, Aug 29]

The economic stakes are significant: a SpaceX IPO market cap that fails to hold the top spot would mark the first time since **2021** that a non-AI pure-play lost the largest-listing crown to a software firm. Historical precedent from the **2020-2021 cycle** shows that when a mega-cap IPO loses more than **25% of its value within the first 60 days**, the probability of it retaining the year’s highest valuation drops below **35%** — a threshold SpaceX has now crossed. With Anthropic’s listing potentially arriving as soon as **October 2026**, the final quarter will determine whether SpaceX can stabilize its share price above **$150**, a level analysts at Neuberger Berman note is critical for maintaining its lead. The next catalyst is the company’s Q3 earnings report, expected in **mid-November**, which will provide the first full-quarter financials including xAI’s contribution. [BBC, Jul 13]

Traded on Polymarket — $881K Volume