When Charles Myers, the chairman of a financial advisory firm, hosted four relatively unknown Democratic congressional candidates at his Midtown Manhattan home last month, he netted more money than he can remember collecting from an event that wasn’t headlined by a presidential candidate.

“More than ever in my 26-year career on Wall Street, donors are willing to look way beyond concerns of overregulation from Democrats,” said Mr. Myers, a longtime Democratic fund-raiser. They just want to elect “Democrats to serve as a check” on President Trump.

The stock market may be booming. Unemployment is hitting record lows. Republicans pushed through $1.5 trillion in tax cuts.

But despite all that, for the first time in a decade, the broader financial community is on pace to give more money to Democratic congressional candidates and incumbents than their Republican counterparts, according to data from the Center for Responsive Politics, a nonpartisan group that tracks campaign donations.