The further declines in US house prices and sales and deteriorating consumer confidence expected in this week’s data releases could add to the market volatility that is unsettling investors.

Existing home sales for January, due on Monday, are forecast to fall from 4.89m in December to a new cycle low of 4.8m. Declines in new home sales have been even quicker, with January’s data, due on Wednesday, expected to show a fall from 604,000 in December to 600,000.