Look around for mentors. If you can get a good mentor, you will be significantly better than you would be otherwise. It's impossible to say what will be 'hot

Look around for mentors. If you can get a good mentor, you will be significantly better than you would be otherwise. It's impossible to say what will be 'hot' five years from now, so you might as well go for what you can become good at. (I'm assuming you are talking about deep knowledge that takes a while to obtain... if you mean a month or two of studying, ignore me.)