SAN FRANCISCO — Mark Frank, who runs a health technology start-up called SonderMind, had planned to wait until the end of 2020 to raise more money for his company.

But after Uber and Lyft stumbled when going public and WeWork ousted its chief executive and pulled its initial stock offering, Mr. Frank changed his mind. With so much disappointment clouding start-up land and an economic slowdown looming, he decided that having more cash on hand was the better course .

SonderMind, which raised $3 million in April, has 80 percent of that money left, Mr. Frank said. To increase the start-up’s “runway,” or the amount of time before it runs out of cash, he decided to spend less than planned, and to be extra safe, he began informal conversations with investors for a new round of fund-raising early next year.

“The question is now, ‘Do we push that timeline up even further?’” said Mr. Frank, 41, who is based in Denver.