[KingOfCoders]

Because they will change their mind?

"demand and supply"

OPEC is a cartel constraining supply to increase prices, it's not a free market but an example of "demand and supply" in it's most brutal form. OPEC prices are not about "gambling".

[jimbob45]

OPEC has gambled several times in the last decade on future oil prices (and not always won).

[KingOfCoders]

In which way has OPEC gambled on future oil prices that moved prices? To my limited understanding this would involve buying oil futures.

[jpgvm]

You don't need to use derivatives to gamble, they control the supply but that control is a lagging control. Any decision they make is essentially a bet about where the oil market is going to move in several months. They are usually big enough that any move they make is going to set the tone but that isn't always the case.

They need to make continual bets on the health of transports, changes in energy mix etc in order to move or keep the price in a favorable band for them. Misstep and the price of oil falls, cutting into their profits or push it too high and face demand destruction and shale extraction coming online because it's profitable at those higher prices, increasing competition and stifling volumes simultaneously.