Democratic presidential candidate Sen. Amy Klobuchar (D-MN) walks with members of Culinary Workers Union Local 226 on a picket line outside of Palms Casino Resort on February 19, 2020 in Las Vegas, Nevada. Mario Tama | Getty Images

As two billionaires pile staggering amounts of cash into their 2020 Democratic presidential campaigns, several of their rivals are burning through money much more quickly than they are raising it. Former New York Mayor Michael Bloomberg shelled out $220.6 million in January as he put $263.8 million of his own fortune into his presidential bid, outspending his opponents by a huge margin, according to Federal Election Commission records filed Thursday. Liberal activist and former hedge fund manager Tom Steyer blew out the remainder of the field by piling nearly $65 million of his own into the race and spending $52.9 million during the month of January.

Sen. Bernie Sanders, I-Vt., led the nonbillionaire Democratic White House hopefuls in raising $25.2 million and finishing the month with $16.8 million in the bank. Sen. Elizabeth Warren, D-Mass., took in about $11 million. Former Vice President Joe Biden, former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Amy Klobuchar, D-Minn., followed with $8.9 million, $6.2 million and $5.5 million, respectively.

Some campaigns burned cash at a rapid pace in the month before the primary nominating contests started. The Buttigieg and Warren campaigns both spent at least twice what they raised — a cause for concern as the race moves toward March 3. On that day, the 14 Super Tuesday primaries will award more than a third of all pledged delegates.

Warren's campaign even took out a $3 million loan, but only tapped into $400,000 of it in January. The filings offer a snapshot of the contenders' fundraising success and spending before Americans started picking the presidential nominee in Iowa and New Hampshire earlier this month. They do not capture the money candidates have raised or shelled out ahead of Saturday's Nevada caucuses.

A handful of candidates — particularly Sanders, Klobuchar, Warren and Buttigieg — have said they saw fundraising boosts following the Iowa caucuses and the New Hampshire primary or the two primary debates this month. Klobuchar and Warren apparently needed the cash injections: their campaigns had only $2.9 million and $2.3 million, respectively, in the bank at the end of January. Sanders has consistently proven the strongest fundraiser among the Democratic White House hopefuls who do not have billions of their own dollars to spend on the race. He appears to hold the strongest position in the race for the nomination. The senator emerged from Iowa and New Hampshire about even with Buttigieg in the delegate count, and polls from Nevada and key Super Tuesday states California and Texas show him leading the field.