Pimco, WisdomTree and Xtrackers posted more than $4bn in collective outflows from their European ETF arms over the past six months, as the boom in the sector shows signs of losing steam.

Figures from consultancy ETFGI show that Newport Beach-headquartered Pimco — the world's largest bond house — suffered outflows of $1.7bn between January and the end of June, the highest redemptions recorded by any European ETF provider.