U.S. Banks Net Interest Margin (FDIC, Quarterly)

## What this measures

Interest income minus interest expense in the quarter, annualized, as a percent of average earning assets (loans, securities and other interest-earning assets), for all FDIC-insured institutions.

## Why it matters

The margin is the core of bank earnings: the spread between what banks earn on loans and securities and what they pay depositors and lenders. It shows how changes in interest rates reach bank profits.

## How to read it

Higher is better for banks. Its lowest readings since 1984 came in 2021, with rates near zero, and it rose as rates climbed until deposit costs caught up. Read it with the cost of funds (credit.banks.qbp.cost_of_funds).

## What it does not say

It covers FDIC-insured commercial banks and savings institutions (insured branches of foreign banks are left out), not credit unions or nonbank lenders. It is an industry figure: the largest banks move it most, and it says nothing about any one bank. The FDIC revises recent quarters as banks amend their Call Reports. The industry margin is pulled up by credit card lenders and down by large banks with big securities and cash holdings.

## Source

Federal Deposit Insurance Corporation, Quarterly Banking Profile, "QBP time series spreadsheets" workbook (sheet "Ratios by Asset Size Groups", block "Quarterly Net Interest Margin", row "All Insured Institutions"), linked from fdic.gov/quarterly-banking-profile each quarter. Public domain: the FDIC data catalog (fdic.gov/data.json) licenses its banking data under the U.S. public domain label, use restriction "Unrestricted". Source: FDIC. Refreshed weekly by /api/cron/credit-banks-sync, which re-reads the full history from the newest QBP.