What are open market operations?

The short answer

Open market operations are how the Fed actually creates or destroys reserves. The Federal Open Market Committee (FOMC) sets policy direction; the New York Fed’s trading desk executes through purchases and sales of securities with primary dealers. When the desk buys, the seller’s bank receives new reserves. When the desk sells, reserves are extinguished.

Two distinct types of OMOs exist. Outright purchases or sales permanently change the balance sheet — these are the QE and QT mechanisms. Repurchase agreements (repos) and reverse repos add or drain reserves temporarily, typically overnight. The choice depends on whether the desired effect is permanent or transitory.

The 1990s and 2000s saw OMOs as small daily affairs, fine-tuning reserves to keep the federal funds rate near target. The 2008 crisis transformed them into trillion-dollar interventions. The 2020 unlimited QE represented the largest OMO program in history, with the Fed buying Treasuries and MBS at unprecedented pace.

→ New to monetary plumbing? Financial education hub

What the data shows

FRED data on Fed assets (WALCL) reveals the dramatic shift in OMO scale across the post-2008 period.

Key figures (FRED, 2008-2024) :

• Fed total assets : $0.9tn (Aug 2008) → $4.5tn (2014) → $8.97tn (Apr 2022 peak)
• Treasury holdings : $478bn (Aug 2008) → $5.77tn (Apr 2022)
• Agency MBS holdings : $0 (2008) → $2.74tn (Apr 2022)
• ON RRP peak (Dec 2022) : $2.55tn
• QT 2022-2024 reduction : ~$1.7tn through April 2024
• Sept 2019 emergency repo peak : >$200bn single-day

The exception worth noting: during the September 2019 repo crisis, the Fed had to deploy emergency repo operations to inject reserves, peaking at over $200 billion in single-day operations. This demonstrated that even in the ample reserves regime, temporary OMOs remain essential for crisis management.

→ Dataset: Fed balance sheet dataset

Why it happens — the macro mechanism

OMOs operate through three distinct logics depending on their purpose.

Short-rate management. In normal times, OMOs adjust reserve levels to support the federal funds rate target. Pre-2008, this meant fine-tuning reserves daily because banks needed precise reserve levels to meet requirements. Post-2008, this role has diminished as the ample reserves framework relies more on administered rates (IORB, ON RRP). Linked to how the Fed controls short rates.

Long-rate compression (QE/QT). Large-scale OMOs target long-duration assets to compress yields across the curve. By removing long bonds from private hands, the Fed reduces term premiums and supports asset prices. The 2009-2014 QE programs and 2020 unlimited QE used this channel intensively. QT reverses the operation. See QE vs QT.

Liquidity provision. Emergency OMOs add reserves during stress. The 2019 repo crisis OMOs and 2020 facilities exemplified this. These operations are designed to be temporary, supporting market functioning without permanently changing the balance sheet structure.

The transmission to broader markets depends on whether OMOs encounter scarce or abundant private demand for the targeted securities. When private demand for long Treasuries is weak, Fed purchases compress yields significantly. When private demand is already strong, the marginal effect is smaller — a key reason QE3 had less measured impact than QE1.

Open market operations are the Fed’s plumbing — invisible when functioning, decisive when stress reveals their importance.

→ Framework: Monetary regimes

What it means for different economic actors

Primary dealers are the Fed’s direct counterparties for OMOs. They earn fees on transactions and use the operations to manage their own inventory. The list of primary dealers — currently 24 institutions — has expanded over time but remains exclusive.

Bond investors watch OMO direction closely because Fed purchases or sales directly affect supply-demand dynamics in Treasury and MBS markets. Coupon issuance schedules, MBS reinvestment patterns, and runoff caps all matter for forecasting Treasury supply.

Money market participants use the ON RRP facility and Standing Repo Facility as backstops. The ON RRP rate sets a floor for repo rates; the SRF caps them. Together, these standing facilities provide the framework within which daily OMOs operate.

A common error is treating QE as the only OMO. In normal times, daily small OMOs continue to manage reserves and short rates, even when no QE program is active. The Fed’s trading desk operates daily regardless of major policy announcements.

Practical observation

Go deeper

Related questions

• How does the Fed create money?
• QE vs QT differences
• How does the Fed control short-term rates?
• September 2019 repo crisis

Frequently asked questions

Who decides which securities the Fed buys or sells?

The FOMC sets broad policy direction — including the size and composition of asset purchase programs — through directives issued after each meeting. The trading desk at the New York Fed implements the directive operationally, choosing specific maturities and timing within the FOMC’s parameters. The desk publishes operational details such as monthly purchase schedules and operation times to ensure transparency. Major decisions like launching QE or initiating QT are explicit FOMC choices; daily implementation choices fall to desk discretion.

Why doesn’t the Fed buy corporate bonds in normal OMOs?

The Fed’s OMOs are limited to Treasuries and agency MBS in normal conditions, partly by the Federal Reserve Act and partly by policy choice. Buying corporate bonds picks winners and losers among private firms, which raises political and credit risk concerns. The 2020 emergency Primary Market Corporate Credit Facility temporarily extended Fed purchases to corporate bonds and ETFs under Section 13(3) authority, but this was an emergency exception that has since expired. The 2024 framework keeps OMOs narrowly focused on Treasuries and agency securities.

How transparent are OMOs?

Modern OMOs are highly transparent. The Fed publishes operation schedules, results, and balance sheet data weekly. The H.4.1 release every Thursday shows asset changes by category. The SOMA (System Open Market Account) holdings are reported in detail. This transparency is a major change from pre-1990s practice when many operations were not announced. Critics argue that some emergency facilities have less granular disclosure, but routine OMOs are among the most transparent central bank operations in the world.

Last updated — 28 April 2026