Donald Trump speaks during the Palm Beach County GOP Lincoln Day Dinner at the Mar-A-Lago Club on Sunday in Palm Beach, Fla. (Wilfredo Lee/Associated Press)

Donald Trump put $6.9 million more of his personal money into his presidential campaign in February, significantly increasing his investment as he began racking up wins in the Republican presidential primary contest, new filings show.

Since he began his White House bid last year, the billionaire real estate developer has lent or given his campaign nearly $25 million, according to Federal Election Commission reports. Although he maintains that he is self-funding the effort, his supporters have contributed $9.5 million, including $2 million in February.

As Trump barreled through Iowa, New Hampshire and South Carolina, he raced through nearly $9.5 million, largely on media buys ($3.46 million), printing and design services ($1.1 million) and event production ($587,000). Trump campaign manager Corey Lewandowski’s New Hampshire-based consulting company was paid $75,000 for the month, including $25,000 the day after the Iowa caucuses.

The GOP front-runner’s overhead was much lower than that of his top remaining rival, Sen. Ted Cruz (Tex.). Cruz sped through $17.5 million in February, his costliest month so far, running down his cash reserves.

The senator raised $11.9 million last month, up from the $7.6 million his campaign collected in January. But Cruz entered March with $8 million in the bank, down from the $13.6 million he had at the beginning of February.

Campaign officials maintained that he has sufficient resources to carry him through the primary season.

“Strong cash position to fund campaign thru June 7th!” campaign manager Jeff Roe tweeted.

The third remaining Republican in the race, Ohio Gov. John Kasich, faces a more dire financial predicament. He pulled in only $3.4 million last month, leaving him with just $1.25 million as he headed into the March primary contests.

The governor spent $3.6 million in February, more than he raised, a rate that puts him on track to quickly run out of cash unless his fundraising ramps up significantly.

On the Democratic side, Sen. Bernie Sanders (Vt.) continued his intense spending pace in February as he scrambled to catch up with former secretary of state Hillary Clinton.

Sanders outraised Clinton for the second month in a row, pulling in $43.5 million to her $30.1 million, according to a Sanders campaign official. But the new figures also indicate that he plowed through far more cash, spending $40.9 million to her $34.3 million. That left the senator with $17.2 million in the bank as March began, while Clinton had $30.8 million.

In all, Sanders has raised just under $140 million, powered by nearly 2 million donors who repeatedly give small amounts online. Clinton, who this month secured her 1 millionth donor, has brought in nearly $161 million overall for her bid.

One of the starkest themes to emerge in the new reports was how mega-donors seeking an alternative candidate to Trump have exhausted millions of their personal wealth — to little effect.

Maurice “Hank” Greenberg, a former head of American International Group who gave $10 million to a super PAC backing former Florida governor Jeb Bush last year, dumped an additional $5 million into a group supporting Sen. Marco Rubio (Fla.) in February. Both candidates have since dropped out.

Marlene Ricketts, the matriarch of the family that owns the Chicago Cubs, invested $4.9 million into a super PAC allied with Wisconsin Gov. Scott Walker before he bowed out of the race last year. This year, she and her husband, J. Joe Ricketts, gave $5 million to Our Principles PAC, which has led a counterattack against Trump.

Ronald Cameron, the chief executive of poultry company Mountaire Farms, first sought to bolster former Arkansas governor Mike Huckabee, plowing $3 million into his allied super PAC last March. Last month, he was the biggest donor to the pro-Rubio Conservative Solutions PAC, shelling out $5 million.

Cameron’s contribution helped the pro-Rubio super PAC scoop up $25 million in February as wealthy donors moved over to the senator after Bush’s exit. Conservative Solutions collected 11 donations of $1 million or more, including $2.5 million apiece from hedge fund billionaires Paul Singer and Kenneth C. Griffin.

Rubio also enjoyed the best fundraising ever for his campaign in February. He raised $9.5 million, nearly double what he collected in January. But by March 15, he was out after losing his home state of Florida to Trump.

Bush, meanwhile, was forced to pump nearly $407,000 of his personal money into his campaign in its final weeks as it struggled to pay bills.

While Bush’s campaign was running out of cash, his allied super PAC still had ample resources. Right to Rise USA raised just under $179,000 in February but still ended the month with $16 million left of its $119 million haul.

In all, since beginning his run last year, the former governor lent or gave nearly $800,000 of his personal money to his White House campaign, raising $34.6 million in total.

Bush spokeswoman Kristy Campbell said in a statement that Bush “remains incredibly grateful for the tremendous support and enthusiasm his candidacy generated, including contributions received from individuals in all 50 states and Washington, D.C.”