It is a perennial problem facing the biggest holders of equities such as pension funds and other institutional investors – how to build or reduce those positions without the market moving against you. The issue has come into sharp focus in recent months as investors have rediscovered an appetite for equities, forcing a rotation back into the asset class through large repositioning trades.

Inflows to US equity funds hit $18.3bn in the first week of January, according to data provider Lipper, the fourth-largest inflow since records began in 1992.