It's only when the markets are perceived to have exhausted themselves on the downside that they turn. Trying to prevent them from going down just merely prolongs the agony.

There do appear to be, at a minimum, signs of froth in some local markets,

Derivative instruments were bystanders, ... They may well have intensified the losses in underlying markets, but they were scarcely the major players.

The problem is you cannot have free global trade with highly restrictive, regulated domestic markets.

Instead of trying to contain a putative bubble by drastic actions with largely unpredictable consequences, we chose, as we noted in our mid-1999 congressional testimony, to focus on policies to mitigate the fallout when it occurs and, hopefully, ease the transition to the next expansion.

If I turn out to be particularly clear, you've probably misunderstood what I've said.