The Fed Needs to Tread Carefully in Twitchy Money Markets

It might not be time to really get nervous about US money markets, but it’s definitely time to pay more attention. Signs of strain emerged as September turned into October this week — it wasn’t completely wild, but the tensions were the worst since early 2020.

The Federal Reserve isn’t yet concerned, but still this shouldn’t be happening right now. This week’s jump in borrowing costs suggests a couple of scenarios: Either large banks need more spare cash than the Fed has assumed, in which case it will have to halt its quantitative tightening sooner than it plans; or there are blockages in the financial plumbing that mean banks’ reserves aren’t as mobile as they should be and the central bank needs to work out why.

Getting this wrong could generate severe disruptions in repo markets, where hedge funds and dealers swap Treasuries for short-term cash loans from money-market funds, banks and others. There were huge spikes in repo rates in September 2019, the last time bank reserves got too low. This matters because these money-market rates are the foundations of borrowing costs for almost everything else, interfering with the Fed’s monetary policy.

Lending capacity in money markets often gets tested at the end of a quarter. This is when banks and dealers rein in their activities and shrink their balance sheets so they can meet capital requirements in their reported accounts.

However, the puzzle is why this quarter provoked repo market strains. US banks still have nearly $3.2 trillion of spare reserves, which is the special money used for payments between banks, the Fed and the Treasury Department. That total is plenty compared with the amount the Fed considers to be ample, which is equivalent to 9% of gross domestic product, or about $2.7 trillion. Plus, the central bank in 2021 created a permanent stigma-free short-term lending facility that is meant to alleviate any emerging strains as they appear and put a ceiling on repo rates.

banks have plenty