The working capital tranche requires instant accessibility to clear daily sovereign payment instructions. To earn a return on this ultra-short liquidity pool without accepting unsecured bank credit risk, central banks use Tri-Party Repo Markets.

A tri-party repo transaction injects the central bank’s overnight cash into commercial dealers, utilizing an independent clearing bank to manage the operational logistics:

Central Bank injects cash -> Clearing Bank moves collateral to Central Bank account -> Dealer repurchases next day with interest

The clearing bank acts as a neutral agent, handling daily collateral valuations, executing margin calls, and verifying eligibility criteria automatically. This structural separation isolates the central bank from operational settlement risk and secures its overnight lending lines.