Reid Hoffman, a founder of LinkedIn and a longtime venture capitalist, is no longer the public face of the venture firm Greylock. Michael Moritz, a force at Sequoia Capital for 38 years, officially separated from the investment firm last summer. And Jeff Jordan, a top investor at Andreessen Horowitz for 12 years, left in May.

They are among the most recognizable of a generation of Silicon Valley investors who are getting out of venture capital at the end of a lucrative 15-year upswing for the industry.

Many more are leaving. Investors at Tiger Global, Paradigm, Lightspeed Venture Partners, Emergence Capital and Spark Capital have all announced plans to step back. Foundry Group, a venture firm in Boulder, Colo., that has backed 200 companies since 2006, said in January that it would not raise another fund.

Taken together, the steady thrum of departures has created a sense that venture capital — a $1.1 trillion corner of finance that invests in young, private companies, sometimes spawning enterprises like Apple, Google and Amazon — is in a moment of transition.

“We’re at a tipping point,” said Alan Wink, a managing director of capital markets at EisnerAmper, which provides advisory services to venture capital firms. While there have been waves of retirements in the past, he said this one was more pronounced.

The turnover creates an opening for new investors to step up, potentially shifting who the power players are in Silicon Valley. That may also change the calculus for young companies as they decide which venture firms to seek money from.