among other reasons - because the limit is so large
it doesn't halt until a $10 per move.
with oil at 60, that's a 16% move.
so, it's a much larger move to get a halt, then the amount necessary for ags to lock limit
notice also that crude does not lock limit (as in shut down for the day) when this amount of movement occurs. it is a 5 minute halt only
there is no maximum move. theoretically oil could trade right to zero without a close
i'd be a buyer at that level
quoted from the NYMEX site:
Maximum Daily Price Fluctuation
$10.00 per barrel ($10,000 per contract) for all months. If any contract is traded, bid, or offered at the limit for five minutes, trading is halted for five minutes. When trading resumes, the limit is expanded by $10.00 per barrel in either direction. If another halt were triggered, the market would continue to be expanded by $10.00 per barrel in either direction after each successive five-minute trading halt. There will be no maximum price fluctuation limits during any one trading session.