Money Supply (M1) and the Stock Market

A reader commented: “M2 cannot be an accurate money supply measure because it includes non-cash investments such as money market mutual funds. When the stock market corrects and people are exchanging stocks for say, money market mutual fund shares, the M2 figure will actually increase. The money supply is not literally increasing in such cases as no new cash is being created; there is merely an exchange of existing assets. Technically, only increasing the monetary base would increase the money supply, but M1 is a reasonable substitute for that as it includes the cash part of bank reserves.” The M1 money stock consists of funds that are readily accessible for spending: currency in circulation, traveler’s checks, demand deposits and other checkable deposits. Is there a reliable relationship between historical variation in M1 and stock market returns? Using weekly data for seasonally adjusted M1 and the S&P 500 Index during January 1975 through January 2021, we find that: (more…)