New banking regulations require large financial institutions to hold enough “easy-to-sell assets,” in order to survive an economic crisis.

Now, the big banks are uncertain whether or not their $1.1 trillion of aggregated mortgage debt qualifies as this type of asset, according to an article in Bloomberg.

The headline of the article states, that as a result, the new banking regulations leave the largest financial institutions “guessing” about what counts as liquidity and what does not:

Left unclear was whether some or all of a type of bonds known as agency collateralized mortgage obligations can count toward the liquidity coverage ratio approved this week by U.S. banking regulators.

The government-backed debt, which isn’t explicitly mentioned in the rule, represents a big part of bank holdings. Wall Street banks create the investments by bundling existing bonds into notes with varying risks, meaning they help support the broader mortgage-backed securities market that funds and…