Nikki Haley had an eye-popping month of fundraising in January, hauling in almost as much cash as the prior three months combined, Axios has learned.

Why it matters: The Haley campaign has the money to keep her long-shot presidential bid alive, even as many leaders in her party have called for the GOP primary to come to an end.

• Haley raised $16.5 million in January, including $11.7 million from grassroots supporters, according to her campaign.
• The campaign also added 69,274 new donors last month.

Zoom in: Haley brought in more than $5 million in online grassroots donations the week after New Hampshire. She saw a surge in support after Trump threatened to bar any Haley donor from "MAGA camp."

• "It was just a sort of gasoline on the fire," said Mark Harris, the lead strategist for the pro-Haley super PAC Stand for America.
• Haley has 10 fundraisers over the next two weeks in California, Florida, New York and Texas to continue to make her case to mega-donors who were key to her rise.
• The campaign's January fundraising reports are due Feb. 20.

Zoom out: Haley's campaign raised more cash than it spent in 2023, while rival campaigns like Trump, Florida Gov. Ron DeSantis and Sen. Tim Scott (R-S.C.) all burned through more cash than they brought in.

• "The campaign was smart and was thrifty and was very diligent with how it used its resources," Haley campaign spokesperson Olivia Perez-Cubas told Axios.
• Haley brought in $17.3 million during the fourth quarter, her public FEC filing shows, more than double the $8.2 million she raised during the quarter before that.

By the numbers: Haley had $14 million in cash on hand at the end of 2023.

• Sen. Bernie Sanders had $18.1 million in cash on hand during the same period of the 2020 campaign, while President Biden had $8.9 million.
• Sen. Ted Cruz (R) had $18.7 million on hand in the same period of the 2016 campaign.
• Trump's campaign ended 2023 with $33 million on hand, but his FEC filings show he spent millions of donor money on legal fees, with multiple criminal trials ahead of him.

What to watch: The Stand for America super PAC spent more aggressively and ended 2023 with $3.5 million left in the bank.

• Harris said that it's focused on South Carolina ahead of the state's Feb. 24 primary.
• "We may end up advertising in the Super Tuesday states ... but we're following the campaign's lead and the best thing we can do for all those states is have a strong showing in South Carolina."

The bottom line: "We're the insurgent outsider campaign, we're the underdog," Harris said. "That's right where Nikki likes to be."

Go deeper: How Nikki Haley has unleashed on Trump since New Hampshire