The study looked at how prices are determined for crude oil futures, focusing on WTI and Brent sweet crude. WTI was found to play a bigger role in setting prices compared to Brent, with WTI having over 80% of the influence. This was consistent across different trading sessions, days with major economic news, and even when looking at data down to the millisecond. The price difference between Brent and WTI that started in 2008 did not change WTI's dominant position in price discovery.