SURGE will always pay 15%. That's on every token you own. Right now you can buy it for a big discount so interest is 15%, but the actual yield is almost 21%. That's because of the HIVE price. $72 of Hive will get you 100 SURGE. 100 SURGE will pay you $15 of interest over a year. 15 divided by 72 = 20.83%.
So, $72 turns into $100 when SURGE sells out and trades at $1. So, you get a 39% gain on the SURGE itself, PLUS the 15% interest. After 1 year, you would have $115 from a $72 investment which equals almost a 60% gain.
Now......if LEO goes up and LSTR goes to...say....$100, then you could convert your SURGE to 2 LSTR and sell it for $200. That means that your $72 turned into $200+$15=$215 (a 3x) for a downside-protected, dividend paying, "safe" investment.