US pre-open: Stocks seen lower ahead of Yellen speech

US futures pointed to a lower open on Wall Street on Tuesday as investors eyed a speech by Federal Reserve chair Janet Yellen.

At 1210 BST, Dow Jones Industrial Average and S&P 500 futures were down 0.1%, while Nasdaq futures were off 0.5%.

Yellen is due to make a speech about global economic issues at 1800 BST, with investors likely to be looking for any clues about the timing of the next rate hike. Speeches are also due from Philadelphia Fed President Patrick Harker, Minneapolis Fed President Neel Kashkari and San Francisco Fed President John Williams.

Oanda analyst Craig Erlam said: "Needless to say, this could prompt plenty of volatility throughout the session, as we’ve already seen in the euro and sterling."

In currency markets, the dollar was down 0.7% against the euro at 0.8878 after European Central Bank chief Mario Draghi said "a considerable degree" of stimulus is needed in the eurozone compared to a previous call for "very substantial" stimulus.

The greenback was 0.2% weaker against the pound at 0.7844 after it emerged that the Bank of England will force banks to bolster their capital buffers. In its Financial Stability Report, the BoE said there are pockets of risk that warrant vigilance. It said that increasing the UK countercyclical capital buffer rate to 0.5% from 0% will raise regulatory buffers of common equity Tier 1 capital by £5.7bn. This will provide a buffer of capital that can be released quickly in the event of an adverse shock occurring that threatens to tighten lending conditions.

In corporate news, Google's parent company, Alphabet, was weaker in pre-market trade as the European Commission slapped the tech giant with a record €2.4bn fine for promoting its own shopping comparison service ahead of competitors.

Shares in Sprint surged in pre-market trade following a report that it is in exclusive talks with Charter Communications and Comcast on a potential wireless services deal.

On the macroeconomic front, S&P/Case-Shiller house prices are at 1400 BST, along with the trade balance and Richmond Fed manufacturing index.