There are known concerns that are related to the limited balance-sheet capacity of large dealers to cope with large changes in asset prices, with lower market liquidity globally in some market segments.
That relates to the changing structure of liquidity provision on capital markets, with less liquidity provided by large broker dealers and more by asset managers, which operate under a different set of regulations. This is discussed in the Financial Stability Board and other places. We have the duty to warn market participants that they have to be ready for that.