Tuesday wasn’t just debate night for the 2020 Democratic presidential candidates. It was also the deadline for them to file their third-quarter fundraising reports, as The Washington Post’s Michelle Ye Hee Lee and Anu Narayanswamy report.

As usual, these reports provide a window into the health and sustainability of the campaigns. Money isn’t the be-all, end-all in campaigns, but it is a necessity if you want to compete.

Lee’s and Narayanswamy’s big takeaway is that former vice president Joe Biden isn’t raising front-runner money but is spending heavily; he raised the fourth-most in the field from July through September and has the fifth-most cash on hand.

Here are a few other things we learned.

Feeling the burn (rate)

You know the primaries are getting close when the candidates start spending big. That was certainly the case in the third quarter. All but four of the leading candidates spent more money than they raised, creating a “burn rate” of more than 100 percent. The only exceptions were Sens. Elizabeth Warren (D-Mass.) (75 percent) and Bernie Sanders (I-Vt.) (84 percent), South Bend, Ind., Mayor Pete Buttigieg (95 percent) and Andrew Yang (43 percent).

(Side note: It seems the guy who wants to give away free money isn’t exactly doing that with his campaign.)

The highest burn rate from a non-self-funder belonged to Sen. Amy Klobuchar, who raised $4.8 million and spent $7.8 million for a burn rate of 162 percent. That’s important because the Minnesota Democrat is still struggling to make the fifth debate. Having dropped so much cash in the third quarter and not making too much headway in the polls isn’t great, which may explain her more combative debate performance Tuesday.

Speaking of trouble: Julián Castro

Making the next debate requires getting to 3 percent in four qualifying national or early-state polls, or getting to 5 percent in two early-state polls. Klobuchar at least has $3.6 million in the bank and one 3 percent poll. The situation for Julián Castro, though, appears more dire.

He raised less than all but two of the 12 candidates on the debate stage Tuesday ($3.5 million), and he has by far the lowest cash on hand ($672,000). With no qualifying polls thus far, a middling performance Tuesday and with very little in the bank to try to improve his lot, it’s difficult to see how he makes that next debate.

Booker’s gambit pays off

With 10 days left in the quarter, news leaked out that Sen. Cory Booker was telling supporters he needed to raise at least $1.7 million down the stretch to stay in the campaign. He got it, and it’s about the only thing separating him from his own pretty dire financial situation.

The New Jersey Democrat has $4.2 million cash on hand thanks to the late $2 million infusion he got. That’s way behind the top five candidates, and it’s also behind Yang ($6.4 million). The good news for Booker is he’s already in the next debate. Now he needs to show some momentum so that he doesn’t have to resort to such gimmicks to raise money.

Steyer’s $47 million self-funding explosion

Klobuchar’s and Castro’s struggle to make the next debate has to be all the more difficult to swallow given the one newcomer in Tuesday’s debate — billionaire Tom Steyer — has already qualified for it. Steyer is one of just seven candidates who are set for the fifth debate at this point.

How has he done it? By absolutely flooding early states with his own money and getting the polls he needs in them. Steyer spent an astounding $47 million in the third quarter, almost all of it from his own pocket and more than doubling what every other candidate spent. Sanders was next in line at $21.3 million.

Sanders wins again, right when he needed to show staying power

Sanders hasn’t exactly kept pace with Warren in national polls, and some of his early-state poll numbers have waned, but he remains the fundraising champion. For the third time in three quarters, he beat everyone else.

For the second quarter in a row, Sanders pulled in a little over $25 million and narrowly outpaced the second-place candidate. In the second quarter, the runner-up was Buttigieg ($24.9 million), and in the third it was Warren ($24.7 million).

Sanders also has the most cash on hand, at $33.7 million — a number buoyed by $12.7 million in transfers from his old campaign committee. That suggests, despite the health problems he faced in the past few weeks and the lack of early traction, he can be in this thing for the long haul if he really wants to.