US pre-open: Dow futures point to fourth straight losing session

As of 1230 BST, Dow and S&P 500 futures were both down 0.23%, while Nasdaq-100 futures had that index opening 0.25% lower.

While the S&P 500 and the Nasdaq managed to finish out Tuesday's session in the green, the Dow closed 22.65 points lower as investors awaited a potentially key testimony from Federal Reserve chief Jerome Powell scheduled to begin at 1500 BST.

Early on Tuesday, Powell delivered the opening remarks at a Boston Fed conference but, as anticipated, made no references to monetary policy ahead of the semi-annual testimony to the House Financial Services Committee.

Powell is expected to discuss decelerating economic activity and increased risks over the next two days - further indicating the Fed's readiness to cut interest rates as appropriate.

However, the world's most powerful central bank was also expected to keep both markets and the White House guessing as to just how deep - and perhaps also how soon - the Fed intends to trim rates.

Overnight, Atlanta Fed president Raphael Bostic said the Fed was debating the pros and cons of allowing the world's largest economy to run "a little hotter".

Elsewhere, Kansas City Fed president Esther George said US inflation was unlikely to surge anytime soon, but noted that keeping interest rates too low for too long could put financial stability at risk.

Ahead of the open, analysts at TD Securities said: "Powell's appearance on Capitol Hill provides the main focus today but we will also keep a close eye on today's BoC policy decision.

"A July Fed rate cut is fully priced and today's testimony should do little to alter this expectation. The path from there is less certain, however, and the USD should follow rates market developments accordingly today."

In corporate news, AngioDynamics, MSC Industrial Direct, Bed Bath & Beyond, and PriceSmart will release their corporate results throughout the course of the day.