Tell you what, just make it very clear here what you want a beta tester to do, because the jump from 100 to 1,000 pre-funded implies there's a lot more work and responsibility... Just specify what's needed, and specify the new terms and conditions, and then you'll get the testers you need.
Otherwise, there's very little to differentiate this and other trading platforms. You accept Bitcoin and other crypto, how about tout some of your blockchain-based different features?
I would be interested, but yes, as mentioned, it would be good to have the details ironed out here.
If you're looking for a set amount of hours for the individual to test your platform (IE: QA), specify that. It'll help weed out the users who are just looking for that deposit amount vs users actually willing to test your platform in exchange for the amount offered.