It actually works really well around oil inventories. I use to trade this. Both for oil and natty. See the purpose of using the OR during a shock event is that is when there is high volume and a lot of players entering and exiting the market. It becomes an anchor. It's the same logic as in the old days using the opening pit times where orders would flood in all over the place. It establishes position levels, stop levels, etc. Even to this day, using these events actually works much better then opening trading times which in the 24/6 electronic world are kind of useless.