Federal banking regulators have proposed a “net stable funding ratio” for depositories with more than $250 billion in assets that aims to ensure that large banks’ lending and investing activities are sufficiently supported by sources of stable funding over a one-year horizon. The proposed NSFR would require banks to calculate a weighted measure of the stability of their equity and liabilities over a one-year time horizon, known as the available stable funding, or ASF, and calculate their level of required stable funding (RSF) over the same one-year period. Beginning in 2018, the proposed rule would require...