“We believe this is a significant hit for real estate brokers, but we don’t think this is over yet at all. There are more battles to be had,” she wrote. “This is the first domino to fall, but the National Association of Realtors is still on the hook.”

Brokerages who chose to settle ahead of the trial said they were pleased with their decision.

“The settlement releases our company, affiliated agents, and franchisees from liability related to these claims. The jury verdict, while disappointing, does not alter our settlement,” said Trey Sarten, a spokesman for Anywhere Real Estate, in an emailed statement.

Those who had lost previous court battles with N.A.R. were celebrating.

Jack Ryan, the chief executive of REX Real Estate, which in August lost an antitrust lawsuit against N.A.R., Zillow and Trulia, has been outspoken about setting commissions lower. In a text message on Tuesday, he hailed the verdict as “extremely good news for Americans.”

If commissions can be lowered, “the price of every home will come down, jobs and wages will go up, tax revenues will increase, people can easily move to better and more fulfilling jobs,” he wrote.

Other lawsuits are now imminent. Within minutes of receiving the verdict on Tuesday, the lawyers for the plaintiffs entered another class-action suit into U.S. District Court in Missouri. That case, filed on behalf of three new home sellers, also claims the practice of having home sellers pay sales commissions to buyers’ agents is a violation of the Sherman Antitrust Act. It names N.A.R. as a defendant, as well as several major brokerages including Compass, eXp World Holdings, Redfin and Douglas Elliman.