OpenAI IPO valuation be between $1.25T and $1.5T priced at 17.4% on Polymarket, down 4.8 points, on $108K traded

OpenAI valuation band loses ground

Polymarket’s contract on whether OpenAI’s IPO valuation will fall between $1.25T and $1.5T was priced at 17.4%, down 4.8 percentage points, with $108K traded, in the supplied market update published Oct 28, 2026, at 2:54 AM ET.

The move reflects a lower market-implied probability for that specific valuation range. It does not establish whether traders shifted toward a valuation above $1.5T or below $1.25T; prices for those alternatives were not provided.

No fresh catalyst identified

The accompanying news summary identified no significant new platform headline in the preceding 30 minutes. It said searches resurfaced material already used on Oct. 27, including the NBA preferred-partner deal and a CFTC-NBA item. The supplied material does not establish a connection between those stories and the OpenAI contract’s decline.

According to predictionbubbles.net, its movers board measures changes over 24 hours and refreshes every 15 minutes using prices from Polymarket and Kalshi. The supplied page records a venue-data snapshot of 28 Oct 2026, 06:45 UTC. It ranks changes in probability points rather than relative percentages.

The source excerpt does not include an OpenAI-specific market row, so the contract’s price, decline and traded amount come from the supplied headline. The $108K figure provides trading context, but the material does not show order-book depth or identify the trades behind the repricing.

What it means for prediction markets

• The signal is range-specific: The 17.4% price concerns a $1.25T–$1.5T IPO valuation, not the probability of an OpenAI IPO itself.
• The decline is measured in points: A 4.8-percentage-point move is distinct from a 4.8% relative decrease.
• Causation remains unconfirmed: Neither the news summary nor the source excerpt identifies a fresh OpenAI development explaining the move.
• Volume is not liquidity: The reported $108K traded does not, by itself, establish how much buying or selling the market could absorb without another price change.