So here I have a friend who's inviting me here on the said gambling investment. It's just simple, you'll send your bitcoin (investment on any amount) on that person then he's going to play using the money collected. After 7 days, your investment will be doubled and the money will be sent back to you after deducting the trans fee. There is a chance of losing but if your money loses, you'll. Be given a 10% refund.
Someone already tried this? Safe or not??
This is a very odd way of investment. You'll invest bitcoin to some gambling maniac? Hell no. You'll just feed his addiction to gambling and this will not turn out beneficial to the both of you. Yes, he might win big but he could lose big as well. Bitcoin is uncertain and you are adding Bitcoin to it? Merging two uncertain things could be a devastating chaos.
I do not recommend this as this have higher risk that Bitcoin alone.