Counterparty

A counterparty is the other party in any financial transaction or contract, and counterparty risk is the danger that they fail to deliver what they owe. When Lehman Brothers failed in September 2008 with over 600 billion dollars in liabilities, thousands of firms worldwide discovered how much of their wealth existed as promises from a single institution.

Why it matters

Nearly everything called an asset in modern finance is actually a claim on a counterparty: bank deposits are loans to banks, bonds are loans to issuers, brokerage balances are entries in someone else's books. In calm times the distinction is invisible. In crises it is everything, because chains of obligation transmit one failure through the whole system. Collateral, clearinghouses, and netting all exist to manage this one risk, and financial history is substantially the history of counterparty failures.

In the gold vs bitcoin debate

Physical gold in one's possession and self-custodied bitcoin belong to a rare category: assets with no counterparty at all, valuable without anyone's promise. This shared property is why the two are compared in the first place. Each surrenders it the same way, gold through unallocated accounts and vault claims, bitcoin through exchange balances, at which point the holder owns an IOU wearing the asset's name. The maxim not your keys, not your coins is counterparty risk translated into bitcoin idiom.