Many an irate bank customer has fumed "But it's my money!" upon being informed they must wait or pay for the privilege of accessing an account. Once the cash is deposited, however, that statement is not entirely true. And when there is a run on the bank, it quickly becomes clear that having cash and having a claim on cash are two very different things.

The same goes for hedge funds. Earlier this week, United Capital Asset Management, a mid-sized Florida hedge fund manager, was forced to suspend redemptions temporarily from several funds holding asset-backed securities. Wobbles in structured finance, provoking Bear Stearns' recent woes, had spooked several investors enough that they demanded their money back in short order.