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OpenAI · Series B

Creator of ChatGPT, GPT-4, and the leading frontier AI lab.

Amount

$1B

Round

Series B

Valuation

Announced

Jan 2021

Investors

Lead investor

Microsoft

Notes

Microsoft follow-on

Other OpenAI rounds

Date Round Amount
Mar 2026 Series E $122B Details →
Oct 2025 Series b $10.3B Details →
Mar 2025 Series D $40B Details →
Jan 2024 Series a $10B Details →
Jan 2023 Series C $10B Details →
Jul 2019 Series A $11M Details →