Earlier this week (30 November), it emerged that the leading credit rating agency had lowered the scores of 15 of the biggest banks around the world by one notch due to the pressures of issues such as the eurozone debt crisis.
Several major lenders in the US experienced a downgrade, including the Bank of America, Morgan Stanley and JP Morgan Chase, while just two out of the 37 firms analysed saw their ratings go up.
In the UK, financiers such as the Royal Bank of Scotland, Barclays and Lloyds suffered score declines and Andrew Fraser, investment director at Standard Life, believes this will "raise concerns about their short-term funding".
"They will be sidelined by money-market funds who are the traditional buyers of that short-term paper," he added.
By Claire Archer