By Tim Reid

(Reuters) - Donald Trump, who predicted three years ago that if Democratic President Joe Biden won the White House in 2020 markets would crash, said on Sunday that stock markets hitting record highs were just making "rich people richer."

Trump, the frontrunner for the 2024 Republican nomination, often took credit for a rising stock market when he was president between 2017 and 2021. He was mocked by Biden last week for wrongly predicting a crash when they campaigned against each other in 2020.

The Dow Jones Industrial Average hit a record high last week, topping 37,000 and surpassing the previous record set in 2022. In a 2020 debate with Biden, Trump said that if Biden won the election, "the stock market will crash."

Biden defeated Trump in the 2020 election.

In an attempt to give a populist and anti-Biden twist on the new record stock market high, Trump, a self-described billionaire, told a crowd of supporters in Reno, Nevada: "The stock market is making rich people richer."

Turning on Biden, he changed the subject to high prices, a hallmark of Biden's three years in office.

"Biden's inflation catastrophe is demolishing your savings and ravaging your dreams," Trump said, as he looks ahead to a likely rematch with Biden in the November 2024 White House contest.

Despite decreasing inflation in recent months, an increase in wages and low unemployment, Trump added: "We are a nation whose economy is collapsing into a cesspool."

Republican voters begin picking their 2024 White House standard-bearer on January 15 in Iowa, the state that kicks off the nominating process.

Trump was holding a rally in Nevada, where Republicans vote on February 8.

Trump enjoys commanding leads over his Republican rivals in state and national polls, despite his myriad legal problems and more than 90 criminal charges bought against him this year.

In a CBS News/YouGov poll released Sunday, however, one of Trump's Republican rivals - former United Nations Ambassador Nikki Haley - had narrowed the gap on Trump in New Hampshire, the second GOP primary state that will hold its primary on January 23.

Trump has 44 percent support of likely Republican primary voters in the Granite State, while Haley has increased her support to 29 percent.

In a clear sign Trump sees Haley as emerging as his closest rival for the nomination, rather than Florida Gov. Ron DeSantis, who has fallen in many polls all year, Trump went after Haley in his Nevada speech.

Citing other polls where he has bigger leads over Haley, Trump said: "Nikki Haley - where's the surge?"

Reporting by Tim Reid; Editing by Mary Milliken and Deepa Babington