Kalshi odds of an Anthropic IPO announcement before Nov. 16 fall to 7 cents

The “Before Nov 16, 2026” contract in Kalshi’s “When will Anthropic officially announce an IPO?” event gave back most of Thursday night’s jump on Friday. As of 10:11 p.m. ET on Friday, Nov. 13, 2026, Kalshi’s market data showed a last trade of 7 cents, against a previous-day price of 16 cents, with the best bid at 6 cents and the best ask at 7 cents. About 315,500 contracts changed hands in the 24 hours to that time, and open interest stood near 739,700 contracts. The contract has traded about 1.64 million contracts since it opened on Oct. 21.

A day earlier the same contract had jumped from 1 cent to 17 cents on Thursday night.

How the price came back down

Kalshi’s hourly price history, labeled by the end of each hour, shows the slide in two legs. After midnight the contract fell from 16 cents to a close of 10 cents in the hour to 1 a.m. ET Friday, then touched 5 cents in the hour to 2 a.m. and closed at 7 cents in the hour to 3 a.m.

It climbed back through Friday morning, closing at 13 cents in the hour to 7 a.m. and trading as high as 16 cents in the hours to 8 a.m., 10 a.m. and 11 a.m. The afternoon took it lower again. It closed at 10 cents in the hour to 2 p.m. and held between 9 and 11 cents until 5 p.m. The busiest hour of the day, the one to 6 p.m., carried about 58,900 contracts and traded as low as 5 cents before closing at 9. The hour to 8 p.m. closed at 5 cents, and the hour to 10 p.m. traded between 5 and 8 cents.

Anthropic’s filing list on the SEC’s EDGAR system shows no filing after the two free writing prospectuses accepted on Thursday morning, the later one at 6:08 a.m. ET, as of Friday night. The list shows no notice of effectiveness and no Form 8-A. No opened record explains the timing of Friday’s moves, so this story does not assign one.

What counts as “officially announce”

The rules are narrower than the event’s name. The market resolves Yes “If Anthropic confirms an IPO before Nov 16, 2026,” and the rules define that: “An IPO is confirmed if 1) the SEC declares the company’s Form S-1 effective OR 2) the IPO is priced OR 3) a securities exchange has assigned a ticker to it. As long as any of those events occur, the market will immediately resolve to Yes, even if the company does not start trading until after Nov 16, 2026.” The contract closes at 11:59 p.m. ET on Sunday, Nov. 15, and can close early if the event occurs.

Anthropic’s filings give these dates. Its second amended S-1, filed Nov. 10, offers 825,000,000 Class A shares at an estimated $70 to $78 each and says the company has “applied to list” on the Nasdaq Global Select Market under the symbol “ANT.” A free writing prospectus that reproduces Anthropic’s IPO website states: “Subject to regulatory clearance, the final IPO share price is expected to be set on November 18th (EST), and shares are expected to begin publicly trading on November 19th (EST).” Neither document gives a date for SEC effectiveness.

The rest of the ladder

The later contracts in the event barely moved. As of the same check, “Before Nov 20, 2026” last traded at 96 cents, against 97 cents a day earlier, on about 10,500 contracts in 24 hours. “Before Dec 1, 2026” stood at 97 cents and “Before Jan 1, 2027” at 98 cents, down from 99. The February, March and April 2027 contracts each last traded at 99 cents. The five earlier contracts, dated from Oct. 1 through Nov. 1, settled No.

Polymarket’s “Anthropic IPO by __?” event asks a different question: it resolves Yes only if Anthropic shares are “listed on a public securities exchange and open for trading” by 11:59 p.m. ET on the listed date. As of 10:11 p.m. ET Friday, its Nov. 15, 16 and 17 rungs each priced below 1 cent and the Nov. 18 rung at about 0.8 cents. The Nov. 19 rung stood at about 93 cents, down 2.6 points on the day, on about $24,900 of 24-hour volume, and the Nov. 20 rung at about 95 cents. The event as a whole traded about $113,500 in 24 hours.

Polymarket traders also marked down Anthropic’s valuation lines. In “Will Anthropic’s valuation hit __ by December 31?”, the $1.75 trillion line priced at about 44.5 cents as of 10:11 p.m. ET Friday, with a last trade of 43 cents, down 5.5 points on the day, on about $36,200 of 24-hour volume. Its hourly history shows it near 50.5 cents on Thursday evening. The $2 trillion line fell 8.5 points to about 24 cents on about $93,600, and the $1.5 trillion line slipped 5.6 points to about 79 cents. The $1.25 trillion, $1.1 trillion and $1 trillion lines have already resolved Yes. That market settles on Nasdaq Private Market’s NPM price and, after an IPO, on the IPO price and the company’s public market capitalization through Dec. 31. Polymarket also runs a separate “Anthropic IPO Closing Market Cap” event, which we covered on Nov. 11.

Our AI news desk researched and wrote this article, and software checked every factual sentence against the records it links to, following the WriterOps methodology. Report an error.