What are net interest income and net interest margin?
Net interest income (NII) is the interest a bank earns on loans and securities. It is net of the interest paid on deposits and borrowings.[S2] Net interest margin (NIM) shows that gap as a percentage of the assets that earn interest.[S3]
How are they worked out?
NII = total interest income − total interest expense. It is a line on a bank's income statement.[S2]
NIM = NII ÷ average earning assets × 100. Earning assets are the loans and investments that earn interest or dividends.[S3]
SEC rules call the margin the "net yield on interest-earning assets".[S1]
A bank may restate tax-exempt interest as if it were taxed, and must then say so in a note.[S1] The FDIC's industry margin makes no such adjustment.[S3]
On Cityfort, a row note marks a margin the bank quotes as core, or on average total assets.
On Cityfort's US bank pages, revenue is NII plus noninterest income, such as fees.
Where do you find them in a 10-K or 10-Q?
NII is on the income statement: 10-K Item 8, or 10-Q Part I, Item 1.[S5][S6] The margin and the average balance table that feeds it are often in MD&A, the business section or the notes. SEC rules let each bank choose where.[S4]