How much is enough? Bear Stearns had money on hand: over $15bn in cash and nearly $15bn in unencumbered assets in its year-end filing. It still went belly-up in spectacular fashion. It is shocking how quickly a broker-dealer's defences can be blown apart in just a couple of days. But just as shocking is the continued crisis of confidence in the broker-dealers yesterday, even after the Federal Reserve's extraordinary move to ease liquidity constraints.

Lehman can point to stronger liquidity than Bear, at nearly $200bn. But its trump card, which Bear did not have, is the knowledge that it can use the Federal Reserve's expanded lending facility, should counterparties in key funding markets decide to shun its collateral. It was rewarded with a collapse in its stock, down a massive 20 per cent on the day - though it is worth pointing out the more encouraging trend in its credit default swaps, which effectively measure the cost of insuring against default. There are probably several things going on. First, there may be so much panic that some investors may not have absorbed the significance of what the Fed has done to ease liquidity. Alternatively, they may be worrying how it will work in practice if there is a widespread loss of confidence.