Illiquid stock is stock that cannot be sold for cash easily because it is not traded on a public market or in demand by other private investors. Often this means the stock can still be sold or traded but only with a significant discount compared to the potential value it may represent.

Stock in early-stage companies is considered illiquid because there is not a strong secondary market for the stock of companies with no track record and because various regulatory restrictions may apply to the transfer of that stock.