# Secondary Market A market where existing shareholders sell their shares to new buyers, as opposed to the primary market where the company issues new shares. For public companies, the stock exchange is the secondary market. For private companies, secondary transactions happen through platforms like Forge, EquityZen, and Carta, or through privately negotiated deals. Private secondary markets are where the valuation narratives of pre-IPO AI companies get stress-tested. [[OpenAI]]'s $500B secondary-round valuation (October 2025) was set by institutional investors willing to pay that price — but the secondary market also reveals what individual employees and early investors think the shares are worth when they sell. Secondary market prices can diverge significantly from the "official" valuation set by the last funding round. If employees are selling at a discount to the last round's price, it's a signal that insiders view the headline valuation as inflated. If they're selling at a premium, demand exceeds the company's willingness to issue new shares. ## See Also - [[Lockup Period]] — the post-IPO restriction - [[OpenAI Investors]] — secondary pricing in context