October's drop continues a steep downward trend from the unprecedented highs experienced during much of the past two years.

Since April 2021, money supply growth has slowed quickly, and since November, we've been seeing the money supply repeatedly contract year over year. The last time the year-over-year (YOY) change in the money supply slipped into negative territory was in November 1994. At that time, negative growth continued for fifteen months, finally turning positive again in January 1996.

Money-supply growth has now been negative for twelve months in a row. During October 2023, the downturn continued as YOY growth in the money supply was at –9.33 percent. That's up slightly from September's rate decline which was of –10.49 percent, and was far below October 2022's rate of 2.14 percent. With negative growth now falling near or below –10 percent for the eighth month in a row, money-supply contraction is the largest we've seen since the Great Depression. Prior to this year, at no other point for at least sixty years has the money supply fallen by more than 6 percent (YoY) in any month.

The money supply metric used here—the "true," or Rothbard-Salerno, money supply measure (TMS)—is the metric developed by Murray Rothbard and Joseph Salerno, and is designed to provide a better measure of money supply fluctuations than M2. (The Mises Institute now offers regular updates on this metric and its growth.)

In recent months, M2 growth rates have followed a similar course to TMS growth rates, although TMS has fallen faster than M2. In October 2023, the M2 growth rate was –3.35 percent. That's down from September's growth rate of –3.35 percent. October 2023's growth rate was also well down from October 2022's rate of 1.42 percent.

Money supply growth can often be a helpful measure of economic activity and an indicator of coming recessions. During periods of economic boom, money supply tends to grow quickly as commercial banks make more loans. Recessions, on the other hand, tend to be preceded by slowing rates of money supply growth.

It should be noted that the money supply does not need to actually contract to signal a recession and the boom-bust cycle. As shown by Ludwig von Mises, recessions are often preceded by a mere slowing in money supply growth. But the drop into negative territory we've seen in recent months does help illustrate just how far and how rapidly money supply growth has fallen. That is generally a red flag for economic growth and employment.