It depends on what the rest of your CV looks like, but I'd lean towards leaving it off. It will be better suited to being included in cover letters and answers to specific application questions. On a graduate programme or internship, for example. It would also be good to mention in interviews, so long as you can clearly explain some of the strategies you choose and what you have learnt from the experience so far.
I agree with Daniel. It's better to mention it during interviews and share what strategies you used and what you've learned. And also your motivation behind why you started doing it in the first place.
I also agree with Alex and Daniel...we must also remember that the psychology behind real money accounts and demo accounts are hugely different. Fear is one of the hardest things to control...but strategically beneficial when trying to plan and create trading ideas.