I've been to a conference for undergraduate GSMs in tech, and while I don't have any statistics, it felt like there were almost as many transwomen/genderqueer presenting as female as there were women (and still many more men and transmen). I think it's super awesome that tech is as welcoming to trans people as it is and has been from other people's stories that I've heard. I'm just worried that it isn't as sensitive to bi-cis-women as trans folks and gays or lesbians.
Me too, it's great that tech is accepting of them. The ratios worry me though. I don't think trans women are drawn to tech just because it's trans-friendly, I think women are pushed away from tech but trans womens' unique circumstances mean they stay, or something like that.
Maybe it's complicated by the fact that many people transition after the point where they already have ideas or plans for their future careers. One woman I talked to actually transitioned in between getting a job offer at a major tech company and starting the job.
For the record, she said that everyone was really open and comfortable with it, and one of the first things her boss did was make sure that all her IDs and employee records were updated to reflect her actual gender identity, which was awesome.