(Jan 18): US stock index futures were little changed on Wednesday ahead of another set of big bank earnings and Federal Reserve Chair Janet Yellen's speech.

Goldman Sachs and Citigroup are scheduled to report results before market opens. Goldman, like most of the big US banks that have reported results so far, is expected to post a jump in quarterly profit as the US presidential election in November boosted trading activity.

Goldman's stock was up 0.96% in premarket trading, while Citi slipped 0.3%.

The Trump rally, which drove Wall Street to record highs, has been showing signs of fatigue since the start of the year as investors get increasingly nervous about his unconventional approach to trade and politics.

US stocks closed lower on Tuesday, with some of the biggest beneficiaries of the post-election rally including banks and transport companies, shedding some of their gains.

Yellen's speech will be closely watched to see if she gives the strongest voice to a growing opinion among policymakers that fiscal stimulus under the Trump administration may call for more aggressive interest rate hikes.

The dollar index rose 0.38% against a basket of major currencies

Consumer Price Index is expected to have edged up to 0.3% in December. The report is due at 8:30am ET (1330 GMT).

A reading on December industrial output and a report on the housing market are also scheduled for the day.

Target dropped 4.9% to US$67.50 after the big-box retailer reported a decline in sales during the holiday season and cut its fourth-quarter earnings forecast. Shares of bigger rival Wal-Mart were off 1.3%.

CoLucid Pharmaceuticals surged 32% to US$46.10 after Eli Lilly said it would buy the drugmaker for about US$960 million. Lilly's stock was up 0.3%.

Gigamon dropped 18.6% to US$35.85 after the network traffic management software maker estimated its fourth-quarter revenue to fall below its previous forecast.

Futures snapshot at 6:59am ET:

Dow e-minis were up 6 points, or 0.03%, with 15,071 contracts changing hands.

S&P 500 e-minis were up 0.75 points, or 0.03%, with 78,855 contracts traded.

Nasdaq 100 e-minis were up 3.75 points, or 0.07%, on volume of 13,493 contracts.