Agree here. Inventory data for Crude and NG is important. The figures to compare are expected vs. actual inventory. Logically, this would make one think that if the actual inventory is less than expected the price would go up and vice-versa. But as Catch mentioned, that is not always the case.... However, on inventory days, there is a lot of volatility. Especially around the time the inventory data is released..... So watch out the crazy moves of Crude in the evening... and see the behaviour compared to the data....
Volatility spikes at these events,prices undergo random fluctuations hitting stop losses.