An offer to purchase a bundle of securities without knowing the exact securities being purchased. A blind bid is risky in that the investor is unaware of the composition of the investments being bid on. The risk is that the investor will end up owning worthless securities.
Blind bids are more likely to be used by institutional investors who do not want to influence the overall market by making targeted buy and sell trades, as a blind bid allows them to trade a book of securities. In a blind bid, the investor typically knows whether the counterparty is buying or selling, and is also aware of the number of stocks in the portfolio and their notional values
Institutional investors look at the purchase of securities differently than individual investors, as individual investors use liquidity, volatility and company news to determine what price they want to pay. Instead of trades that could reach into the thousands of dollars and involve a few securities, institutional investors make trades in the hundreds of millions that involve entire books of securities. The larger the blind bid transaction, the greater the risk premium associated with the underlying securities.