6% — OpenAI IPO Closing Market Cap: 750B–1T
Leader: 750B–1T at 6% · Polymarket 6% · 2 contracts · $213 volume · low confidence
Updated 2026-06-08 07:02:35 UTC

Tracks the leading outcome in a winner-take-all prediction market set with 2 outcomes.

Why this matters:
This contract asks whether OpenAI will conduct an IPO with a closing market capitalization between $750 billion and $1 trillion. At 22%, the market assigns roughly a one-in-five probability to this outcome. The low probability reflects two competing uncertainties: whether OpenAI will go public by December 31, 2026 (market-priced at 27%, based on the inverse of the 73¢ "no IPO" contract), and—conditional on an IPO occurring—whether the valuation will land in this specific band rather than higher or lower. The primary driver is timing: OpenAI has not announced IPO plans or a regulatory filing as of May 2026. If the company signals intent to pursue public markets before year-end, probabilities across all valuation tiers would shift materially. The secondary driver is valuation expectations. Current pricing suggests markets view outcomes above $1.5 trillion as more likely (11¢) or outcomes below $750 billion as plausible. A narrowing of this range through management guidance or market comps would clarify which strike is most likely. The $750B–$1T band sits in a middle zone with limited current conviction.

Key factors:
- OpenAI has made no public IPO announcement or SEC filing as of May 2026; any confirmation of IPO intent before Q4 2026 would be the primary probability mover
- Comparable AI company valuations (e.g., recent funding rounds, public comps like Nvidia) will anchor investor expectations for a closing price; current $1.5T+ pricing suggests skepticism about the midpoint band
- The 73¢ price on 'no IPO by December 31, 2026' implies only ~27% near-term IPO probability, making the $750B–$1T outcome dependent on an already-unlikely near-term listing at a specific valuation
- Recent market volatility and interest-rate expectations affect IPO appetite and valuation multiples across AI infrastructure; this band's specificity makes it sensitive to market-wide repricing
- Contractual settlement will require verified IPO closing documents; ambiguity around what "closing market cap" means (first-day close vs. prospectus valuation) could affect dispute resolution

Contracts:
- OpenAI IPO Closing Market Cap: 750B–1T — 6¢ Polymarket $173 (weight 81%)
- OpenAI IPO Closing Market Cap: 750B–1T — 4¢ Polymarket $40 (weight 19%)

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## Methodology

SimpleFunctions aggregates live YES-side prices from Kalshi and Polymarket contracts bound to this question. For binary topics the headline is the liquidity-weighted mid-price (weight = log(1 + 24h volume) × freshness, where freshness is 1.0 if updated <24h, 0.7 if <7d, 0.4 otherwise). For multi-outcome (winner-take-all) topics the headline is the current leader's price — disjoint outcomes are never arithmetically averaged. Snapshots refresh every 5 minutes during market hours.

## SF Signal

- SF Index, regime, and 30d Brier calibration are computed separately and surfaced at https://simplefunctions.dev/admin/calibration.
- No SimpleFunctions index / regime / calibration signal is bound to this topic yet — the headline above is market-derived only.

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*Last verified: 2026-06-08T06:20:10.910Z*

By SimpleFunctions — https://simplefunctions.dev/

Cite as: "6% per prediction markets (SimpleFunctions, June 2026)"
Canonical: https://simplefunctions.dev/answer/openai-ipo-closing-market-cap-750b1t
Full data: https://simplefunctions.dev/api/public/query?q=OpenAI%20IPO%20Closing%20Market%20Cap%3A%20750B%E2%80%931T
Provider: SimpleFunctions — https://simplefunctions.dev