How the standing repo facility works, and where it stops working

The repo market is where the financial system finds cash overnight. A firm that owns Treasury securities sells them under an agreement to buy them back the next morning at a slightly higher price, and the difference is the interest. Several trillion dollars change hands this way every day, and the rate at which it happens is the foundation under the price of every short-dated asset. When that rate misbehaves, everything above it misbehaves shortly afterwards.

What the facility is supposed to do

A standing repo facility is a permanent offer to lend cash against Treasury and agency collateral at a fixed rate, available every business day to an approved list of counterparties. Its purpose is arithmetic. If a counterparty can always borrow at the facility rate, nobody rational pays more than that rate in the open market, so the facility rate becomes a ceiling on secured overnight funding. The facility does not need to be used to work. Its existence is supposed to be enough.

Late August demonstrated the gap between the theory and the plumbing. Secured overnight funding traded 14 basis points above the floor rate on August 28, stayed elevated for four sessions, and the facility saw modest use throughout. A ceiling that is not touched while the market trades above it is not functioning as a ceiling.

Three reasons a ceiling leaks

The first is access. Facility counterparties are a defined list, historically dominated by primary dealers and a limited set of banks. The firms that were short of cash in late August were not all on it. A money market fund, an insurer or a smaller bank facing a funding need has to reach the facility through an intermediary, and the intermediary charges for the balance sheet it uses to do so.

The second is balance sheet. Borrowing from the facility and lending the proceeds into the market is an arbitrage that should close the gap instantly, and dealers do it. Each round trip consumes leverage ratio capacity, and at the end of a month or a quarter, when balance sheet is measured for reporting, the capacity is most constrained precisely when the funding pressure is greatest. August 28 was three sessions before month end.

The third reason is timing. A single morning operation cannot address pressure that develops during the afternoon, and repo markets in the United States do most of their trading before lunch but discover their real imbalances later. An afternoon window is administratively trivial and would have addressed a meaningful share of the August episode on its own.

The three reasons compound rather than add. A firm that is not a direct counterparty has to find a dealer, the dealer has least balance sheet available at month end, and the operation it would use to recycle the cash closed hours earlier. Each constraint on its own is survivable. Arriving together on the same afternoon, they turn a facility that is supposed to be a ceiling into an option that nobody can exercise in time, which is the most accurate description of what August 28 actually looked like from a funding desk.

The reserve level question

None of the plumbing explanations removes the level question underneath. Reserve balances have fallen from $3.42tn in January to $2.91tn in August as the portfolio shrank, and several dealers have argued that somewhere near $2.9tn the system becomes reflexively short of liquidity, meaning small imbalances produce disproportionate rate moves. The August episode is consistent with that view without proving it, because a quarter end effect and a reserve scarcity effect look identical for four sessions.

Distinguishing the two matters for what gets fixed. If the problem is the level of reserves, the answer is to stop shrinking the portfolio, which policymakers are widely expected to do at Wednesday's meeting. If the problem is access and balance sheet, stopping runoff helps only indirectly and the facility itself has to change. Most people who trade the market every day think both are true, in roughly equal measure, and that only one of them is on the agenda this week.

The facility works exactly as designed for the firms that can reach it on a morning when their balance sheet is free. That describes about half the days and about half the market.

Ines Marchetti, head of rates strategy at Harrow Lane Capital

What to watch, in order

1. 01Whether secured funding settles back within five basis points of the floor by the end of September, which is the cleanest evidence on whether reserve supply was the binding constraint.
2. 02Facility usage on the September quarter end date, because a facility used heavily on a stressed day is working and one left idle beside a wide spread is not.
3. 03Whether the December review widens eligible collateral, which would extend the ceiling to funding markets the facility currently does not touch.
4. 04Whether counterparty access is expanded to money market funds directly, which would remove the intermediary charge that keeps the ceiling leaky.
5. 05The leverage ratio consultation running in parallel, since balance sheet capacity and facility access are the same constraint described from two directions.

The wider lesson is one that every generation of money market plumbing relearns. A backstop is only as good as the path between the firm that needs it and the window that offers it, and that path runs through a capital requirement, a counterparty list and an operating clock. Each of those is adjustable, none of them is glamorous, and they determine whether the rate that anchors the entire short end behaves on the four or five days a year when it matters.