You mean you've found some site that promises to double your BTC and the scamming part of escaping you? Don't let yourself be fooled.
It is just a high risk investment game... everyone knows every single site is going scam (and if you do not know, then you are not ready te be on this page).
It's just having luck that you can invest long enough to turn the odds for your profit, so yea, I still believe it IS the same as gambling, though a bit more peculiar since you are promised it will work. And I just like to laugh with people's post where they desperately ask for the refund of their investment lol. Call me a douche I don't care. And I do play on some of these, but even though I always hope to win, I have been pushed from my little pink cloud where magic happens, btc is real, hyip are real, doublers are real, but you ahve to be lucky to know when to get in, and when to stay out. Develop a good system for the latter, and I do believe there is much to be gained... Wish I had the skills to make a website myself. So I could myself try what is found to be a profitable way for both investors and admin... Well perhaps I should learn how to make sites lol