Thoughts on fintech startup!

So, I recently got offered by a fintech startup. Am currently working for a decent pay and they are able to pay me 40% more on my current salary. My concern is not related to pay. If I get in, I will be one of the core members as part of the product while it is being developed. And I have heard from my friends saying fintechs are a risky part to be a part of, especially startups!

Any thoughts would help me widen my perspective! :)