Definitely a good factor to know about, but there's also been a huge surge in things like Monetary Base (currency in circulation+reserves) [0]. Looks to me like there's a lot of (effectively) money printing behind this, not just an artifact of M1's definition?
Wouldn't that be more likely just a large increase in reserves? We know reserves are higher. There also seems to be a shortage of currency in circulation due to COVID affecting the ability to print new bills as old bills come in.
tldr, they think a large portion of the growth is due to a regulation change in April that is causing banks to report savings accounts and other similar accounts in a category that is counted as M1. Graphs indicate that M2 growth is more steady, even though M1 is a component of M2. Which indicates that it is basically just being redistributed from M2 to M1.
