at first. "talk" and "deals" is different things. second. can you trade on "talks"? i am sure you cant. or do you have method? i think you dont.
Prices move because of traders expectation of future prices. When there are rumors that OPEC is going to do this or that, traders make bets based on that I formation. When a deal is formalized traders make bets, when a deal falls through, trades make bets. I trade off of price but I try to keep an ear on major risk events. Holding a shorter term position into a major risk event is pure gambling IMO of course.