Mark Zandi of Moody’s Analytics is getting increasingly worried states are taking a large gamble by reopening businesses too quickly.

He warns a spark in new coronavirus infections would send the economy further into tailspin — especially since there’s no vaccine.

“If we get a second wave, it will be a depression,” the firm’s chief economist told CNBC’s “Trading Nation” on Friday. “We may not shut down again, but certainly it will scare people and spook people and weigh on the economy.”

Zandi defines a depression as 12 months or more of double digit unemployment.