What happened: The Baltimore Orioles acquired infielder Randal Diaz from the Washington Nationals in exchange for right-handed pitcher Kyle Nicolas. The move is a minor league swap and marks the first completed trade between the two franchises.

Why it matters: The Beltway neighbors had never traded with one another before, an unusual gap for clubs separated by roughly 40 miles. Breaking that stalemate, even on a low-stakes deal, removes a long-standing quirk from the sport's trade landscape.

What to watch: Watch whether the two front offices, having finally done business, become more frequent trade partners going forward.