Global assets under management barely grew in 2015, with traditional active managers suffering outflows, according to a survey.

The survey was conducted by consultancies Casey Quirk by Deloitte and McLagan, and was of members of the US Institute and European Institute, forums for senior leaders at investment management firms.

The 2016 survey, the fifteenth annual version, found that there was low growth overall in the global asset management industry, with assets under management (AUM) rising from $68trn (€61bn) in 2014 to $69trn in 2015.

Industry revenue fell, from an estimated $346bn in 2014 to an estimated $344bn last year.

Index-linked and multi-asset class investment strategies attracted more than 90% of net new money worldwide last year.

Of firms surveyed with more than $10bn in AUM, 56% reported positive net flows compared with 60% in 2014 and 63% in 2013.

The share of those reporting negative net flows was up, from 40% in 2014 to 44% last year.

Net flows into passive strategies globally doubled in the past two years to reach 72% of the total in 2015.

Traditional active strategies saw outflows in 2015, “against gains in 2014”, according to the consultancies.

Net inflows into multi-asset class strategies increased from 18% to 24%, while new investments into alternatives fell from 10% to 8% of total net flows in 2015.

Jeffrey Levi, principal at Deloitte Consulting LLP, said: “Individual investors – increasingly sceptical of active management, fee-sensitive and outcome-oriented – are the drivers of industry growth.”

Traditional active managers need to adapt their business models to this environment, which also features increasing scrutiny of fees and more regulatory pressure, he added.

“This shifting marketplace will, in turn, drive greater convergence in the industry across wealth management, asset management, insurance and financial technology,” he said.

Credit ratings agency Moody’s recently predicted traditional active asset management would “shrink substantially” due to the shift towards passive investment.