Letting the LLM explain it more clearly than I can:
What exactly changed according to the FRED definition?
Before May 2020:
M2 included:
M1 (currency in circulation + checking accounts + other transaction accounts)
Savings deposits (including money market deposit accounts, MMDAs)
Small-denomination time deposits (under $100,000, excluding IRA and Keogh balances)
Retail money market mutual fund balances (excluding IRA and Keogh balances)
Thus, M2 = M1 + Savings deposits (including MMDAs) + Small time deposits + Retail MMFs.
After May 2020:
M1 was expanded to include savings deposits and money market deposit accounts (previously, savings and MMDAs were NOT part of M1; they were only part of M2).
Since savings and MMDAs moved into M1, the definition of M2 no longer needs to separately add these categories—they are already captured within M1.
Thus, after May 2020, the Fed simplified the definition to:
M2 = (New) M1 + Small-denomination time deposits + Retail MMFs
But importantly, note the following:
M1 itself was significantly expanded (now including savings and money market deposits), causing M1 to spike substantially overnight.
M2 overall did NOT lose or gain any category. It still includes all the exact same accounts and balances. It simply shifted the categorization of savings deposits and MMDAs into M1, so these no longer need separate listing when describing M2.