repo markets are HUGE - about the size of USD M2! they underpin the global financial system however, there’s not many DeFi protocols addressing this part of the market i may pick it up in the near future if you’re working on something similar - hit me up!
in the end, you get your UST bond back and it makes sense for you to repurchase the bond (collateral) even if the price falls as long as the price fall is < ≈haircut (2% in our case)