The Financial Industry Regulatory Authority (FINRA) published an Investor Alert on auction rate securities (ARS). This provides quite a thorough background on ARS, their auction mechanism and risks of failure, alternatives to ARS, and redemption and liquidity issues.
ARS are issued widely by institutions ranging from closed-end mutual funds, municipalities to student loan trusts. ARS are long-term floating rate securities whose coupon payments are determined at auctions that are typically held every 7 to 35 days. ARS are long-term securities with short-term floating rates. Broker dealers marketed ARS as liquid, short-term cash equivalents. However, ARS auctions failed en masse in February 2008 and proved to be illiquid and unsellable in the short-term. In light of recent history, ARS are not liquid short-term cash equivalents and investors ought to be careful when faced with the prospect of owning an ARS.