It was another down day for U.S markets Thursday.

The Dow Jones industrial average lost almost 2 percent to end the day at 15.660 points.

The Nasdaq lost less than 1 percent to close at 4,266 points. And the S&P 500 shaved 1.23 percent to end the day at 1,829 points.

Global financial investment banks Citigroup and Bank of America each saw shares decline more than 6 percent.

American oil benchmark West Texas Intermediate (WTI) lost nearly 5 percent to fall to as low as $26.06 per barrel, after it opened the day at $27.36 a barrel.

Meanwhile, the global benchmark Brent crude oil fluctuated between $29 and $31 per barrel.

The price of Brent crude saw gains after the U.S. media reported that OPEC and non-OPEC countries could consider an oil production "freeze" -- a proposal by Venezuela -- and the United Arab Emirates said members of the cartel might be ready to trim output if non-OPEC producers would cooperate.