Also, remember, it's not just the inventory report that moves the price one way or another. Remember that traders are also thinking about which way the dollar is likely to move, what movements in the stock market are likely to do to the dollar, etc.

Also, remember that speculators often rely on signals that tell them when to buy or sell. They don't really buy or sell based on the inventory report, they watch other factors, like whether the price has risen or fallen to some longer-term moving average, or any number of other indicators or combination of indicators. For example, a very famous trading system that some large speculators are likely following has still not given a sell signal on oil.