Banks are nudging certain hedge-fund clients to use derivatives instead of actual stocks when placing some bets, an effort aimed at lessening the impact of new capital rules on the banks’ businesses.

The shift generally involves derivatives called total-return swaps that mimic the effects of owning a stock or other asset. In some instances, banks take less of a balance-sheet hit when they are hedging offsetting client positions targeting the same stock using total-return swaps than they would if the bets were made via securities.

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