Some $3.7 billion in retail deposits was invested in Nationwide in September and net deposits reached $8.5 billion.
Graham Beale, chief executive of Nationwide, told the Times: "As the financial markets have experienced unprecedented turmoil in recent months, savers have been looking for a safe home for their money.
"Nationwide is regarded by many as offering both a safe haven and good value and we have seen a significant inflow of savings."
Indeed, Nationwide's savings balances rose by $11.9 billion, boosting the UK's second-largest building society's share of the increase in UK retail savings balances by 15 per cent.
Nationwide is seen to be so 'safe' as it was able to fund all residential mortgage lending in the first half of the year from saver's deposits, according to the Times.
"We have one of the strongest and safest balance sheets of any financial organisation in the UK - our assets are of the highest quality and over 70 per cent of our funding comes from member base retail deposits," confirmed Mr Beale.