Spoonhunter runs the tribe’s Office of Homeland Security, which has used money from federal grants to purchase and install new stream gauges and weather stations across the reservation.

Those gauges offer clues on where the markets are headed, and how the selloff is beginning to ripple through the economy.

A devastating Russian attack against Ukraine on Palm Sunday, coming days after Russian President Vladimir Putin shook hands with President Trump’s top negotiator, is raising doubt about the U.S ...