Dow, S&P 500 and Nasdaq futures rose slightly early Wednesday, a tentative rebound after Tuesday's selloff pushed the Nasdaq and S&P 500 back below their 50-day moving averages.
The Federal Reserve is expected to raise rates, with soaring oil prices and Treasury yields tightening financial conditions ahead of the decision.
The 10-year Treasury yield was hovering near 5%, extending the pressure that has weighed on both stocks and bonds in recent sessions.
Markets had shown brief relief earlier Tuesday, but the latest losses underscore how fragile sentiment remains as investors await the Fed's rate decision and projections.