There are many ways to be a passive investor, some 3m to be precise. That is the number of indices that have flourished as asset managers flock to launch exchange traded funds, ESG-related and thematic funds. 

Traditional securities index publishers and newbies alike are filling demand. In some cases, asset managers play the role of both index creator and money manager. Last month MSCI launched a deck of indices allowing funds to track China megatrends, including smart cities and industrial innovation.

The proliferation is a long way from benchmarking vanilla global equity markets. The volume looks strange next to equities. It is 60-odd times bigger than the number of listed companies, which stood just shy of 48,000 at the end of last year, according to the World Federation of Exchanges.