I backed the truck up in 2018 for Fidelity Treasury Bond Index Fund. Most of of my 401K is in it. It's up 31% in the last year. With almost no management fee. That's all.
Congrats, but you should sell out of that before prices come crashing back down to earth, which they inevitably will after the covid-19 scare passes. It might be a couple of months, but history says that you're going to lose all of that money again over the next two years.
I am well aware of the risk of rising interest rates, but those will be in the toilet due to the lasting effect on the disrupted supply chain.
You're betting against all of documented history.
Also, your concern shouldn't be interest rate risk.
Your concern should be a reversal in perceived credit risk.
You benefited from a flight to quality. While these can persist much longer than one would expect (see LTCM), you will eventually lose.