crypto currency investing, anyone?

I went for fixed rate returns, specifically Tax Sheltered Annuities , 403B. I locked in at 7%.. I dont know anyone who wouldnt have gone for 7% garunteed, Over the past 28 yrs. Plus your contributions are taken off the gross amount of your earnings, and in my case it put me in a lower tax bracket.
My entire gambling experience was $50 lost gambling while on a cruise ship.
The moral of The Rabbit and the Tortise
Race applies here.My grand mother put a small amounts into Exxon stock every pay period. Over a 50 yr period it was worth 800K
Of the 4 other siblings i have, Im the only one retired, early. They will be working for at least the next 10-15 yrs.
I’m curious, 7% the minimum or is that the locked in rate? So can you make more the the 7 percent?