I notice a lot of men who have longer hair are doing more than just wearing them in a ponytail now - they are just twisting them up in to buns, but in a similar style that has always been worn by women. I didn't know this was a thing now, but I've seen some men with a bun sitting at the nape of the neck, but also worn high up just like a woman's up-do.
Some of my male friends do this. Only two types of guys seem to do this... guys who are really into surfing, or guys who are very creative/artistic. Both types are often care about their appearances, probably a little more than the average bloke, so they're more likely to follow current trends, which the male bun is right now. It's okay on guys, some can pull it off really well. But I still prefer a guy with guy hair... short, but enough to run my fingers through.