Markets opened flat early Tuesday, just hours after Congress approved a $900 billion coronavirus relief bill as part of a larger $2.3 trillion spending package.
The Dow Jones Industrial Average was down 42 points, or 0.1 percent, and the S&P 500 was down 3.4 points, also 0.1 percent.
For weeks, markets have been volatile over ever-changing signals about whether Congress would strike a deal on a fifth COVID-19 relief package.
The new aid package extends and expands crucial unemployment benefits, includes a new round of stimulus payments, and reopens a small-business relief program. Trump has until Monday to sign the measure.
Both indexes had opened down on Monday following news of a more contagious coronavirus strain becoming prevalent in the United Kingdom, a development that led to harsher closures and travel restrictions from a slew of countries.
The new strain is not known to be more deadly or resistant to the vaccine.