U.S. crude oil exports jumped back above two million barrels per day in the week ending Feb. 16, which is just the second time this level has been reached since heavy restrictions ended in late 2015.

The last jump: It came in the weeks after Hurricane Harvey took a lot of refinery capacity offline, according to Energy Information Administration data.

There are 2 main trends behind the U.S. becoming an increasingly prominent player in global crude markets — the U.S. oil production boom and the export policy change.

• But there's also lots of variation week to week even as the general trend is upward.
• The swirl of factors behind the most recent weekly surge of roughly 700,000 barrels per day likely include maintenance at Gulf Coast refineries, which leaves more barrels looking for a home.

Quick take: "Crude demand from refineries is down for seasonal maintenance, while U.S. crude production is at all-time highs; the surplus is driving strong exports," Citibank analysts said in a note yesterday.