The market has seen this show before: A key member of the Trump administration walks out the door, leaving the investing world to ponder whether it's the sign of deeper dysfunction that could derail what has so far been a distinctly pro-business agenda.
Previous episodes, though, have resulted in few long-reaching effects, with the bull market resuming its path despite a few hiccups here and there.
Gary Cohn, though, is not Steve Bannon or Anthony Scaramucci or Reince Priebus or any of the other nearly two dozen top officials who have come and gone during President Donald Trump's first 14 months in office.
He was much more.
Cohn was a grown-up in the room, one of the few voices who would push back against key tenets of the president's ramrod style. He was not only a Wall Streeter but also a Democrat, a moderate voice during a time of extremes.
So with his departure as Trump's key economic advisor comes more serious questions, with one rising above all the rest: Can the president push forward a populist agenda that also nurtures the market and the delicate climate of American business sentiment?
Cohn's saga will provide the sternest test yet of the market's faith.