Their stories came out slowly, even hesitantly, at first. Then in a rush.

One female entrepreneur recounted how she had been propositioned by a Silicon Valley venture capitalist while seeking a job with him, which she did not land after rebuffing him. Another showed the increasingly suggestive messages she had received from a start-up investor. And one chief executive described how she had faced numerous sexist comments from an investor while raising money for her online community website.

What happened afterward was often just as disturbing, the women told The New York Times. Many times, the investors’ firms and colleagues ignored or played down what had happened when the situations were brought to their attention. Saying anything, the women were warned, might lead to ostracism.

Now some of these female entrepreneurs have decided to take that risk. More than two dozen women in the technology start-up industry spoke to The Times in recent days about being sexually harassed. Ten of them named the investors involved, often providing corroborating messages and emails, and pointed to high-profile venture capitalists such as Chris Sacca of Lowercase Capital and Dave McClure of 500 Startups.

The disclosures came after the tech news site The Information reported that female entrepreneurs had been preyed upon by a venture capitalist, Justin Caldbeck of Binary Capital. The new accounts underscore how sexual harassment in the tech start-up ecosystem goes beyond one firm and is pervasive and ingrained. Now their speaking out suggests a cultural shift in Silicon Valley, where such predatory behavior had often been murmured about but rarely exposed.