The Bank of New York Mellon Corporation (BNY)

BNY is a custodian bank: it lends less than it safekeeps and services other people's assets, charging by their size.

The core business is safekeeping securities for institutional clients: funds, pension systems, insurers. The bank keeps records, settles trades, collects dividends and coupons, and provides reporting. Fees scale with assets under custody, so income grows with markets and carries almost no credit risk.

The second part is clearing and treasury services, issuer services and foreign exchange for the same clients. Changing custodian is a multi-year project, so the client base is exceptionally stable and competition runs among three or four global players.

There is interest income too: client balances are invested, and results rise with rates. The risks are the industry's — fee compression under client pressure, and operational failures, which cost a custodian more than a retail bank. BNY pays a dividend and buys back stock.