OpenAI's valuation hit (HIGH) $1.5T by December 31 priced at 21.5% on Polymarket, up 8 points, on $121K traded

OpenAI valuation odds rise

Polymarket’s contract on whether OpenAI’s valuation will hit $1.5T by December 31 was priced at 21.5%, up 8 percentage points from 13.5%, in the supplied October 20, 2026 update. Reported trading volume was $121K.

The valuation-threshold contract was among the upward moves in finance. Despite the increase, its price still indicated that traders considered reaching the threshold less likely than not.

What the move captures

According to predictionbubbles.net, its movers board compares market-implied probabilities over 24 hours, using prices from Polymarket and Kalshi refreshed every 15 minutes. The supplied source lists a venue-data snapshot of 20 Oct 2026, 12:10 UTC.

The site ranks changes by probability points, rather than relative percentage gains, and does not use volume or liquidity to determine placement. Its stated coverage includes 2,037 markets that remain live for more than 14 days, with only open contracts that have a valid 24-hour comparison eligible for ranking.

The supplied material identifies no company announcement, financing transaction or other specific catalyst for the OpenAI repricing. It also does not provide the contract’s detailed resolution criteria, so the price change alone does not establish that OpenAI’s valuation has increased.

What it means for prediction markets

• A meaningful shift, not a majority view: The move from 13.5% to 21.5% represents an 8-percentage-point increase, while leaving the threshold outcome below even odds.
• Volume provides limited context: The reported $121K traded does not, by itself, establish order-book depth or explain what drove the move.
• Resolution terms remain important: The supplied material does not specify what valuation evidence would qualify for settlement by December 31.