I used BIL as my proxy for MMFs Even very conservative funds like SHY aren't quite like a MMF. BIL is very close though. We can see that SHY is negative for th

I used BIL as my proxy for MMFs Even very conservative funds like SHY aren't quite like a MMF. BIL is very close though. We can see that SHY is negative for the year, while BIL (and "proper" MMFs like VMFXX / VUSXX / etc. etc.) are all positive / better than cash under a mattress. https://totalrealreturns.com/s/SHY,BIL,USDOLLAR https://totalrealreturns.com/s/SHY,BIL,USDOLLAR I'd argue that when most Bogleheads talk about "cash", they're talking about BIL and MMFs. Something between 0 months to 3-months of maturity. ----- I'd still like to see MMFs working of course. I'm sure there's a minor difference between BIL and VMFXX that I haven't though of... but BIL is the closest thing I can think of to a money-market fund.