Opportunity versus Security

I may have a really cool opportunity of which I can not discuss in detail at this point in time. That opportunity may really stretch me and cause me to learn and grow. It would push me outside my limits and boundaries. This could result in something amazing where I would benefit financially and grow in my skills and experience. Or it could result in failure and not a lot of money.

What do I have to lose? Well, potentially my mind, money, time... 

What can I gain? Money, experience, skills, personal and professional growth...

Which would you chose and why? 

This could all unfold before Christmas... I feel like I'm on the Superman rollercoaster for the first time, climbing up, up, up, up that really high hill knowing that at some point I am going to reach the top. It's exhilarating and exciting but also twists my insides and makes me really nervous. Eventually I can put my hands up and let my stomach fly up into my chest and enjoy the ride, but for now that anticipation is getting the best of me.