"We think the Fed will have to be more proactive than it will envisage this week," says Pantheon Macroeconomics' chief US economist.

The Federal Open Market Committee (FOMC) wrapped up its regularly scheduled two-day policy meeting by cutting the short-term federal funds rate by 50 basis points (bps), or 0.5%, to a target range of 4.75% to 5%. Markets were essentially split on whether the Fed's rate-setting committee would ease by 25 bps or 50 bps heading into the decision.

Trump attributed the rate reduction to either a "very bad" economy or to the Fed's "playing politics" to help Democrats.