The number of unsold homes on the American market has risen by more than 1m over the past year, a gain of a third, increasing the prospect of a rapid cooling of the US property market. The inventory of new and existing homes waiting for buyers is now approaching 4m.

The surge in unsold homes has been largely due to a release of new properties on the market rather than a sharp slowdown in sales. This suggests that many sellers are eager for one last payout before the halcyon days of the market draw to a close. Speculative buyers may also be trying to exit the market before conditions deteriorate.