I'm not sure. "Start Trading Bitcoins" is a bit generic and long, but may be fine when always visible. "Get access" may not be something one would even be requi

I'm not sure. "Start Trading Bitcoins" is a bit generic and long, but may be fine when always visible. "Get access" may not be something one would even be required to sign up for. An advantage of "Sign Up" is it's consistency: My usual flow is that I'll look around the website to see whether it's something worth signing up for and when I finally decide to do it something like "Start trading Bitcoins" might throw me off. Here's another sign-up-related UX-crime however: Disrespecting your current users. A lot of services bundle their log in/sign up functionality and prioritize the "sign up" part so much that it becomes incredibly hard to find, especially when it's a fancy short sign up form that looks like one for logging in. It always sends a clear signal about how much you care about people signing up to your service vs. people actually using it. Tumblr is a great example of the opposite: They just present a "log in" page by default and make the "sign up" a little harder to find: This creates just a tiny bit of FOMO ("huh, how do I sign up? Is it invite-only?") and makes the user feel better about actually signing up. Of course Tumblr is a social medium for teenagers and not a SaaS, but in general anything one is expected to use at least semi-frequently should not be difficult to log in to. A good option is to put the forms on equal footing or just ask for the e-mail address and direct the user depending on whether it's already registered.