Two weeks after the US election, hundreds of allies gathered at the White House to soothe Joe Biden in defeat. Tracking the closed-door bash for clues was a group rarely interested in the routine preening of Washington: arbitrage traders.

President Joe Biden has rejected the nearly $15 billion proposed deal for Nippon Steel of Japan to purchase Pittsburgh-based U.S. Steel.

Senior administration officials had reservations about calling Nippon Steel’s takeover proposal a “national security risk.”