A strong year for money market fund flows was set to go out with a bang.

US MMFs took in nearly $55 billion during a holiday-shortened, six-day stretch to December 24, the penultimate “week” of 2024, data released late Thursday showed.

The outsized haul erased two weeks of outflows with plenty to spare, pushing total AUM to a new record high in the process.

As the figure shows, the mountain of cash parked in MMFs is now more than $6.8 trillion tall.

You know the story: Some strategists of a bullish persuasion view that sideline cash as a possible source of funds for an extension of the equity rally or as another source of demand for corporate debt. Others note that outflows from MMFs typically don’t begin in earnest until nine or so months after the Fed starts cutting rates, and the December FOMC meeting anyway suggested rates won’t fall as quickly as markets anticipated just a few weeks ago, perhaps leaving MMF balances “stickier.”

With a few days left on the calendar, MMFs have seen nearly $920 billion of net inflows this year, after $1.15 trillion in 2023.

Since the beginning of 2023 — which is to say if you measure from before the regional banking mini-crisis prompted some depositors to consider “substituting” MMFs for savings accounts given that ultimately, you’re backstopped by the same “full faith and credit” pledge either way — inflows to US money funds exceed $2 trillion.

Cash returned more than 5% for a second straight year in 2024. The last time cash posted comparable back-to-back returns was 2006-2007, and before that 2000-2001.