What you are describing is basically selling a binary call option not a loan. Binary options are fairly popular among retail traders, and are generally sold ra

What you are describing is basically selling a binary call option not a loan. Binary options are fairly popular among retail traders, and are generally sold rather than bought by institutional firms. So it might be hard to find someone to take the other side of that trade. Edit: I'm not saying it's a bad idea. There might be tax reasons to structure this a loan, but looking to binary option pricing might give you a good idea on ow much "interest" you might expect to pay.