The upheaval over sexual harassment in the technology start-up industry mushroomed on Monday, with the resignation of a prominent Silicon Valley investor who said he had been “a creep” and more women saying they would come forward to talk about their experiences.

Dave McClure, the founder of the start-up incubator 500 Startups, said he was stepping down on Monday after The New York Times reported last week that he had come on to a woman who was applying for a job at his firm. Mr. McClure apologized for his behavior over the weekend, in a post titled “I’m a creep. I’m sorry.” Another partner at 500 Startups, Elizabeth Yin, also resigned this weekend, saying that she was quitting after the firm had covered up a separate harassment episode by Mr. McClure.

Several other start-up investors have also issued mea culpas for not doing enough to prevent sexual harassment, with some around the world beginning to strategize over how to avert the episodes in the first place. The New England Venture Capital Association, a trade group, last week invited its members to sign an anti-discrimination and sexual harassment statement. In Australia, start-up entrepreneurs also issued a statement condemning the behavior.

And women entrepreneurs, emboldened by the support, have over the last few days become more willing to share their stories.