I think there is a maximum change per day allowed on the NYMEX, around $5 I believe.

I just checked:

It's $10/barrel (exception on last day of contract before expiration) on the two front month contracts.

There is also allowance to a 200% expansion of the range depending upon when the trading limit is reached (the market is closed for an hour to allow for an orderly transition to the expanded range except when the limit is reached in the last hour of the trading day, and then the market is closed, except on contract expiration day).

The land of the free?

Potentially the land of "lock limit" up / down. However, $10 is one whopper [technical term?] of a daily price movement.

I'm very much a free markets sort, but with margins being what they are, without limits a particularly violent short covering rally [or conversly a liquidation of longs] could mean instant insolvency for half the market and an almost unimaginable cascade of counter party default disasters in OTC derrivatives.

No thanks.

$10/day is nothing. Good thing they've got a little stopper! I feel safer. Don't you?

Ha Ha.

Plan B anyone? Oh, I mean Plan C.