Cosmologists call it the ‘Big Crunch’ – a calamitous end for the universe, in which gravitational forces slow and eventually reverse its expansion, causing space to collapse in on itself.

The theory has been largely discredited in recent decades, but scientists might want to pass their research notes to participants in foreign exchange markets. After years in which trading had fragmented across an ever-greater number of venues, there are signs the market may have reached a turning point, with