Major US stock markets closed with a slight increase against the backdrop of a collapse in oil prices and investor caution ahead of key political and economic developments on Thursday.

The elections in the UK, the meeting of the European Central Bank and the testimony of the former director of the FBI Komi before the Senate group are on the market radar.

Komi's first public appearance since his dismissal by US President Donald Trump is expected to shed more light on the FBI investigation into alleged Russian interference in the US presidential election last year. However, the testimony may also damage the reputation of the Trump administration and undermine its chances of passing through Congress any of the reforms it promised.

Oil prices fell by more than 4%, which was due to the publication of data from the Ministry of Energy of the US, which indicated an unexpected increase in oil reserves. Also, concerns about the efficiency of production cuts in the OPEC deal are also putting pressure on quotes due to the growing tension in relations with Qatar and the growth of oil production by the US.

Most components of the DOW index recorded a rise (18 out of 30). Leader of the growth were shares of NIKE, Inc. (NKE, + 1.56%). Most fell shares of The Coca-Cola Company (KO, -0.97%).

Most sectors of the S & P index finished trading in positive territory. The leader of growth was the financial sector (+ 0.7%). Most fell sectors of main materials (-1.4%).

At closing:

DJIA + 0.18% 21,173.35 +37.12

Nasdaq + 0.36% 6.297.38 +22.32

S & P + 0.16% 2.433.10 +3.77