If you have guaranteed 5% return on your money why aren’t you gobbling it up immediately? And the answer is because you have low confidence that it will outpace inflation

When 10y bond yield is low say 1-2% you’re probably going to put that into the s&p500 because that’s a better place to park a large chunk of money for a better return over time even though that 1-2% is guaranteed. And then you also get risk of “if it goes from 2% to 3% my collateral that was once $100m is now crushed by x%” (I don’t think it moved exactly correlated with the bond’s % yield return it’s a different scale if im not mistaken) so it’s a worse investment