We analyze the content of the Organization of the Petroleum Exporting Countries (OPEC) communications and whether it provides valuable information to the crude oil market. To this end, we derive an empirical strategy which allows us to measure OPEC’s public signal and test its credibility. Using Structural Topic Models, we identify in OPEC narratives several topics related to fundamental factors such as demand, supply, and speculative activity in the crude oil market, highlighting that OPEC announcements are highly linked to oil market volatility and traders’ positions. Most importantly, we find that OPEC communication is credible, reduces oil price volatility, and prompts market participants to rebalance their positions.