Infinity, it turns out, lasted a little more than two years. In September 2012, the US Federal Reserve administered one of the greatest market shocks of recent years by announcing it would buy $40bn of mortgage-backed securities every month (subsequently raised to $85bn, including Treasury bonds), and do so indefinitely.

This was unprecedented. The third dose of “QE” bond purchases was soon dubbed QE Eternity, or QE∞. As the market was not signalling great concern over deflation, and bond yields were low, the complaints were that QE∞ was unnecessary, and meant the abandonment of the dollar. The Fed was telling investors to buy gold, avoid paper money, and invest anywhere in the world but the US.

It has not worked out that way. Ten-year bond yields are higher. Gold has tanked. The dollar stayed weak against its main trading partners until June this year; since then it has appreciated by about 7 per cent. Benchmark mortgage rates, about 2 per cent at the time, dipped, but are now about 3 per cent.