Democratic presidential candidates are sprinting to hit their fundraising goals before the end of the year, a final test of their financial strength before primary voting begins in February.

While candidates typically bombard supporters during the last days of the fundraising quarter, their appeals this week come with a sense of urgency: The figures will signal to supporters and donors whether the candidates can survive the expensive early primaries.

So a few campaigns are taking a different approach to generate money over the next few days.

In an email to supporters Friday, Sen. Elizabeth Warren (D-Mass.), one of the top raisers of the campaign so far, announced that she had amassed over $17 million, about two-thirds of her previous quarterly total.

Candidates typically keep a tight lid on their hauls until after the fundraising deadline passes. But Warren’s campaign made its figure public, then asked supporters to help the campaign hit $20 million in the next few days.

On Christmas Eve, Pete Buttigieg’s campaign launched a contest for supporters to donate the smallest amount possible. “All you have to do to win is donate the smallest amount that nobody else donates. In other words, suppose you donate $1.00. If someone else playing also donated exactly $1, you both lose. We’ll see if only one player donated $1.01, and so on until we find an amount donated exactly once, and that’s our winner,” the email reads.

The South Bend, Ind., mayor’s campaign team billed it as a fun and geeky end-of-year game, in which supporters can challenge each other to donate the lowest amount. But the challenge drew ridicule among skeptics, who called it a “cynical ploy” to drive down the campaign’s average donation amount amid criticisms of Buttigieg’s frequent fundraisers with wealthy donors.

This year’s large field of candidates, along with debate qualification rules that emphasize the candidates’ ability to draw donors, have led to unusual candor among candidates about how strapped for cash they are.

Candidates have plead with their supporters for cash, and they have even announced that they would shutter their campaigns if they do not meet a certain fundraising target. These tactics have worked so far for many, including Sen. Cory Booker (D-N.J.), whose 10-day push at the end of the third quarter brought in a much-needed boost in donations.

The last day of the fundraising quarter is Dec. 31; the campaigns’ finance filings are made public through the Federal Election Commission on Jan. 31.

But candidates with large hauls typically reveal their figures early, setting the bar for the rest of the field and generating buzz around their finances. Candidates who hold off on revealing their numbers often face questions about their delay.

Longtime campaign fundraisers say the first two primary contests could cost upward of $75 million per candidate, and fundraising and spending figures could indicate whether the campaigns will have enough money to face off on Super Tuesday in March.

Some candidates have acknowledged this pressure in their fundraising appeals. “Everyone — our opponents, the media, undecided voters — will be looking at our public numbers to predict how we’ll fare in this tight race,” read a Joe Biden campaign fundraising email sent Thursday.

Keeping up the tactic he introduced in the third quarter, Booker sent an email Thursday itemizing the campaign’s spending needs and publicizing his $800,000 fundraising goal.

And businessman Andrew Yang announced a $3 million goal this week, after which his campaign acknowledged in a message to supporters that it has had “a very slow start” toward that goal.

“Everyone seems to be heading out early to visit with family and friends for the holidays, and fundraising has fallen short at the worst possible time,” his Christmas Eve message read. “We just simply haven’t made enough progress on this goal.”

Such efforts have proved to be successful so far, thanks to the ease with which Democratic donors can give online in response to email and social media fundraising appeals.

On Sept. 30, the final day of the previous fundraising quarter, donors giving in low sums online on the fundraising platform ActBlue gave more contributions in a single day than ever before on the platform.

“We saw unprecedented engagement, with donors giving nearly 40,000 contributions per hour at the peak of end-of-quarter traffic” on Sept. 30, according to ActBlue.