Goldman Sachs and Morgan Stanley each suffered at least ten days of trading losses in the second quarter, underlining how turbulent markets have cast a pall on Wall Street since April.

The banks' trading results deteriorated sharply from the first three months of the year, before uncertainty about the US economy, European sovereign debt and the fate of new financial industry regulation sapped investors' confidence.

Goldman's traders had lost money on 10 separate days during the second quarter, the bank disclosed yesterday in a filing with the US Securities & Exchange Commission.

On three occasions, they posted shortfalls of at least $100m. Goldman earned at least $100m on 17 days.

The bank's traders, along with their counterparts at JPMorgan Chase, made money on every single business day during the first quarter, a first for each.

Goldman's trading desk recorded a profit of at least $25m on each of that quarter's 63 working days, making more than $100m a day on 35 occasions.

The first quarter is traditionally Wall Street's strongest, providing up to one-third of the sector's annual profits, and market volatility would push many corporate and institutional clients to the sidelines not long after the next period began.

Goldman said last month that revenue from trading and principal investing had tumbled during the second quarter, paced by an 89 per cent decline in equity trading. The bank suffered an uncharacteristic blow-up earlier in the period, when it could not hedge against exposures to stock market turbulence in time to avoid losses.

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