Soon after formally introducing Sen. Kamala Harris as his running mate, former Vice President Joe Biden and the California Democrat team up for a virtual grassroots fundraiser on Wednesday.

But the money’s already rolling in for the newly announced Democratic ticket.

KAMALA HARRIS WINS PRAISE FROM TOP PROGRESSIVES DESPITE PAST PRIMARY FRICTION

In the four hours after the presumptive Democratic nominee announced on Tuesday that Harris would be his running mate, the Biden campaign hauled in a whopping $10.8 million in grassroots contributions through ActBlue, the main online nonprofit fundraising platform used by Democratic campaigns and organizations. The figure was first reported by The New York Times and confirmed by Fox News.

While the Biden campaign declined to disclose how much total money was raised, the former vice president tweeted late Tuesday that “Thanks to supporters like you, we are on track to have our biggest fundraising day ever. Together, we can win this.”

The record for a single Biden fundraiser appears to be $11 million, which was the amount brought in by the former vice president when he teamed up with his one-time boss, former President Barack Obama, at a combined grassroots and top-dollar donor fundraiser in late June.

Harris helped Biden bring in campaign cash even before she was picked as the Democratic Party's vice-presidential candidate. A fundraiser in early June headlined by the former vice president and the senator brought in nearly $4 million.

President Trump’s re-election campaign said last week that it, the Republican National Committee (RNC) and its joint fundraising committees combined brought in an eye-popping $165 million in contributions in August. They also touted that they now have more than $300 million cash on hand as of the end of July.

TRUMP TOPS BIDEN AS BOTH TOUT LARGE JULY FUNDRAISING HAULS

The combined Trump campaign/RNC haul was a record and is up more than $30 million from the $131 million it raised in June. The war chest total appears to be a slight increase from the $295 million they had in their campaign coffers at the end of June. The campaign spotlighted that July was their largest online fundraising month ever.

The announcement from Trump’s re-election team came a couple of hours after Biden’s presidential campaign reported that it, the Democratic National Committee (DNC) and its joint fundraising committees combined hauled in $140 million last month.

The former vice president’s campaign also touted that they now have a $294 million in cash on hand as of the end of July, an increase of $50 million in their coffers over the past month.

The $140 million brought in during July is roughly equal to the $141 million the Biden campaign and the DNC raised in June, which was by far the campaign’s best monthly figure to date.

The president’s been raising money for his re-election bid since entering the White House three-and-a-half years ago. And the re-election effort’s hauled in an unprecedented $1.1 billion the past two years.

The former vice president, who declared his candidacy in April of last year, struggled to bring in cash for much of his campaign. He raised just $8.9 million in January and $18 million in February. But he saw his fundraising spike starting in March, as he became the clear frontrunner for the Democratic nomination and much of the party coalesced around his White House bid. Biden became the presumptive Democratic presidential nominee in April, as his last remaining primary rival – Sen. Bernie Sanders of Vermont – dropped out of the race and backed the former vice president.

The Biden campaign surge in fundraising the past couple of months – it narrowly outraised the Trump campaign in May and June – helped it trim the president’s once-massive cash-on-hand advantage.