The start-up enemies of Wall Street are booming

Times are flush for young tech companies like Stripe and Coinbase, which are having a moment as they upend the financial establishment

In 2009, Shamir Karkal and several colleagues struggled to raise money for a banking start-up, Simple. Most of the 70 venture capital firms they met over the course of a year didn’t see the point of the idea, he said. The few that did thought it would fail.

By last year, things had changed. When Mr. Karkal set out to raise funding for his new financial technology start-up, Sila, which makes regulatory compliance software, he garnered $5 million in a few months with a fraction of the pitches. He said he was frustrated it didn’t happen even faster.

“I know folks in