Traders at New York Stock Exchange
Traders work on the floor of the New York Stock Exchange (NYSE) on March 21, 2017 Spencer Platt/Getty Images

The US's main market benchmarks all fell over 1% on Tuesday, their biggest loss in at least five months as investors worried that President Donald Trump's reform plans might not come as quickly as they had first hoped.

The Dow Jones Industrial Average fell 237.85 points, or -1.14% to finish at 20,668.01 and the Nasdaq fell 107.70 points, or -1.82% to end at 5,793.83, their worst single day drops since September. The S&P 500 fell 29.45 points, or -1.24% to finish at 2,344.02 - its worst fall in five months.

CNN Money suggested that the market weakness could be a sign that "the market tone has shifted to a more negative one, at least temporarily". Although the markets have been bullish, a long period of optimism could lead to a similar drop.

Many commented that Trump's legislative agenda, a regulation cutting, business friendly plan that had encouraged many, was being held up by everyday politics and not leading to the immediate action many had hoped for.

"I think that investors are kind of starting to discount the likelihood of the immediacy of [Trump's] policies and the enthusiasm has come off the boil as a lot of his policies got mired in the legislative process," said chief investment officer Jack Albin, quoted in MarketWatch.

"President Trump's legislative agenda is getting mired in a congressional swamp, as starry-eyed optimism runs headlong into bloodshot realism," Albin was also quoted as saying by CNN Money.

Some of the biggest drops came from banks, with Bank of America (BAC) finishing 6.18% lower; JPMorgan Chase (JPM) similarly fell around 3%. Car manufacturers equally did not fare well, with Ford (F) falling 4.56% and Fiat Chrysler (FCAU) losing 5.31%, even though oil prices are falling.