Wall Street may be repeating the mistakes that felled American International Group Inc, which sold the equivalent of cheap lottery tickets in the belief that no one ever would hit the winning number.

These tickets are credit default swaps, derivatives that insure against a company default on its debt. The problem is banks and brokers look as if they are selling these swaps too cheaply, at least for a raft of industrial companies.

The willingness to gamble like this may be symptomatic of the exuberance that has gripped markets this summer. And although the risk is likely far less than that faced by AIG, it shows Wall Street has a tendency to forget the lessons of a crisis as soon as they are learned.