They had been depicted as the bad boys of the buyside, the ones who have given the skilled practice of active fund management an inglorious name. So much so that, in recent months, closet indexers have drawn scrutiny from Scandinavia, UK and even the European Securities and Markets Authority.

Closet indexing involves fund managers charging the high fees associated with the brain-intensive job of picking stocks and then simply buying the stocks in an index, something that could be done by computer at much lower cost. It is largely viewed as misleading and delivering bad value for money for end investors.