Pete Buttigieg, the mayor of South Bend, Indiana, and a fast-rising 2020 Democratic presidential candidate, announced Monday that he raised more than $7 million since launching his presidential exploratory committee in January.

"This is just a preliminary analysis, but our team’s initial report shows we raised over $7 million dollars in Q1 of this year," Buttigieg tweeted. "We (you) are out-performing expectations at every turn. I'll have a more complete analysis later, but until then: a big thank you to all our supporters."

Buttigieg was the first 2020 Democratic candidate to announce his fundraising haul for the first quarter of 2019, an important indicator of a candidate's viability in what's shaping up to be a crowded Democratic field. All of the candidates have until April 15 to release their fundraising totals from the first quarter, which spans Jan. 1 to March 31.

Other Democratic candidates were quick to announce their initial hauls after launching their presidential bids, with former Texas Rep. Beto O'Rourke topping the list at $6.1 million earlier this month in his first 24 hours as a presidential candidate. Vermont independent Sen. Bernie Sanders came in a close second last month, with $5.9 million in his first day as a candidate.

Sen. Kamala Harris of California initially collected $1.5 million and Sen. Amy Klobuchar of Minnesota raised $1 million in 48 hours, as did former Colorado Gov. John Hickenlooper. Gov. Jay Inslee of Washington raised more than $1 million in the first few days. Sen. Elizabeth Warren of Massachusetts raised at least $300,000 on New Year's Eve, her first partial day in the race, according to filings from the online donation clearinghouse ActBlue. But her campaign declined to disclose their complete one-day fundraising picture.