Amid charges that banks manipulated Libor, the benchmark used to price an estimated $800 trillion of loans and derivatives, financial firms are looking for an alternative short-term rate, says the Wall Street Journal.

Nomura and UBS are testing a rate linked to repurchase agreements, called the GCF Repo index. While Libor reflects a survey of banks' estimates of their borrowing costs, the GCF index reflects rates paid for repo agreements, which banks use for short-term funding. Critics note that repos are less risky than the loans that are reflected in Libor, since repos involve collateral.