Towers rose across San Francisco to house the money. The marble was polished. The bathroom floors were warm. The private pools were being filled.

“The world has changed in a year,” said Herman Chan, a real estate broker with Sotheby’s International. “We expected an upward trajectory at least, and it really kind of deflated. These companies aren’t dying but the cultural zeitgeist, that momentum of I.P.O.s, is gone. You don’t even hear anyone talking about it anymore.”

The developers who had fought the odds of regulation and zoning to build their glass residences in the sky had timed their units to the I.P.O.s. But on a recent visit with the Four Seasons sales team, they acknowledged that techie wealth was not what they were seeing. Interest was mostly coming from overseas buyers, young heirs to foreign fortunes and older executives looking for city pieds-à-terre, they said.

Also in time for the wave that was not a wave are more luxury towers: The Avery, The Harrison, 181 Fremont, The Mira.

“The definition of luxury is scarcity, and there’s so many now,” Mr. Chan said. “Nowadays, my buyers are getting a contingency period and inspectors. Things you would never ask for before. There’s not 10 offers on a house anymore.”

Case in point: A full-floor apartment in San Francisco’s poshest neighborhood of Pacific Heights was listed at $21.6 million and advertised that “a sommelier-worthy wine cellar awaits 1,500 of your most prized bottles.” But more than a year later and after a $5 million price cut, it is still on the market.

Prices for the top 5 percent of San Francisco area real estate listings — the cream of the crop — rose 7 percent between 2017 and 2018. This year, they have fallen more than 1 percent, according to data prepared for The New York Times by the real estate listing service Zillow.