"Stocks don't exist in a vacuum, however. Investors have a choice between the expected returns on stocks or the guaranteed returns on Treasury bonds. The higher the price one pays for a security, the lower the expected return. Today, Treasuries (and their close cousin cash) are trading at very high prices historically, though they have dropped a bit of late.
Cash is more "expensive" to own than ever before: it yields either zero if held in the form of currency or in some savings deposits, and a minuscule 0.09% if held in the form of ultra-safe and extremely liquid T-bills. Meanwhile, inflation is running at least 1.5% per year. So the real return on cash is negative: holding cash implies losing about 1.5% of your purchasing power every year."
(The Outlook for Growth Continues to Improve dated 11/03/2020 by Scott Grannis, Chief Economist with Western Asset Management from 1979-2007)
Full article can be found here: http://scottgrannis.blogspot.com/2020/11/the-outlook-for-growth-continues-to.html