When Synapse Investment Management, a London asset manager, revealed last week that it was closing a $300m (£148m, €216m) fund, its decision sent an ominous message for bankers and accountants around the world.

That was because the death knell came not as a result of huge tangible losses on the fund's investments; instead, the main trigger was that the fund had become embroiled in a bitter, secretive fight with Barclays Capital, its prime broker, about valuation issues - how to price the debt instruments the fund held.