Auction Rate Securities (ARS) were marketed by broker-dealers to investors, including individuals, corporations and charitable foundations as liquid, short-term, cash-equivalent investments similar to traditional commercial paper. ARS's liquidity and similarity to short-term investments were entirely dependent on the presence of sufficient orders to buy outstanding ARS at periodic auctions in which they were bought and sold subject to a contractual ceiling on the interest rate the issuer would have to pay. If the demand for an ARS was too low to clear the market, broker dealers sponsoring the auction could place bids just below the maximum interest rate to clear the auction. The lower the public demand for an issue, the larger the quantity broker dealers had to buy to avoid a failed auction.
Participating broker dealers had better information than public investors about the creditworthiness of the ARS issuers and were the only parties with information about the broker dealers' holdings and inclination to abandon their support of the auctions. This severe asymmetry of information made public investors in ARS vulnerable to the brokerage firms' strategic behavior. In this paper, we explain what auction rate securities were, how they evolved, how their auctions worked, and why their flaws caused them to become illiquid securities.