The amount of assets deemed hard-to-value dropped at top US banks by 4% in the three months to end-June, having surged by almost one-fifth over the first quarter of the year.

Level 3 assets, those for which market prices are not available and are instead valued using firms’ own models, totalled $131 billion as of end-June across the 23 US banks over $100 billion in size.

The quarter-on-quarter drop was sharper at the eight too-big-to-fail banks than at their non-systemic peers. In aggregate, Level