Prediction markets put the probability at 70%: Will Anthropic IPO by October 31, 2026. Currently, markets see this as likely (70% YES). The Polymarket event “Anthropic IPO by \_\_?” currently prices year-end 2026 as more likely than not.
Trading on the **Anthropic IPO by October 31, 2026** contract has shifted dramatically since early July, with the implied probability of a listing by that date rising to **70%** from **36.5%** on July 7. The catalyst was Anthropic’s confidential **S-1 filing with the SEC on June 1, 2026**, followed by a targeted pricing window of **October 15 to November 15** at a fully-diluted valuation between **$1.10 trillion and $1.25 trillion**, according to a Tech-insider report citing Forge Global. The proposed primary issuance size of **$25–35 billion** would make it the largest U.S. listing since Saudi Aramco’s Riyadh debut, a scale that has historically compressed the timeline between filing and pricing for mega-cap tech deals. [Tech-insider, Jun 04]
The market’s repricing reflects a narrowing gap between the **October 31 deadline** and the **December 31, 2026** contract, which still trades at **75.5%** implied probability. Shorter-dated lines have collapsed: the **September 30** contract sits at **9.5%**, while the **July 31** line is at **0.7%** and the **June 30** contract has already resolved NO. This steep decay curve is typical of late-cycle IPO windows, where regulatory review and roadshow logistics—not demand—become the binding constraint. Anthropic’s confidential filing on June 1, 2026, followed Bloomberg’s late-March report that the company was considering an October listing, a sequence that mirrors the 2020 Snowflake IPO, which filed S-1 on August 24 and priced on September 16, a 23-day gap. [247wallst, Jul 07]
What happens next hinges on two data points: the **SEC’s comment letter process** and Anthropic’s **Q2 2026 earnings**, which are expected to show the company on track for profitability sooner than OpenAI. The company has not publicly confirmed a listing date, but multiple investment banks and The Financial Times have corroborated the **October 2026 window**. If the S-1 becomes effective by late September—a 90-day review cycle consistent with recent large-cap filings—the **Anthropic IPO by October 31** contract would likely converge toward the year-end line. Conversely, any delay in the comment letter response or a market-wide volatility spike, similar to the August 2024 yen carry trade unwind that postponed several tech listings, would push the probability back toward the **30% NO** side. [Moomoo, Jul 31]
Polymarket prices this at 70c YES with $410K in volume. Moderate liquidity — use limit orders for positions above $1K to avoid moving the price.
Smart money positioned NO.
We tracked 1 wallet with positions above $1K on this market.
| Wallet | Category | Side | Amount | P&L | |
|---|---|---|---|---|---|
| 0x7c3d..6b | MM | YES | $1.6K | +38% |
YES wallets entered between 45c. At current price 70c, all YES holders are profitable while all NO buyers are underwater. Profitable positions rarely sell early — YES side has structural price support.
Polymarket prices YES at 70c with $410K in total volume. Our model estimates fair value at 70c. Model and market are aligned — no pricing discrepancy detected.
| Platform | YES Price | Volume |
|---|---|---|
| Polymarket | 70c | $410K |
| Our Model | 70c | — |