Big Tech Dominance Is Forcing Index Superpowers to Rethink Rules

The Big Tech boom is causing headaches for all-powerful index providers on Wall Street, who can send billions of benchmark-tracking dollars on the move with just a stroke of the pen.

Two of the world’s biggest – FTSE Russell and S&P Dow Jones Indices – are presenting plans to undercut the weighting of the largest megacap companies in key indexes. The rare intervention comes as the US equity market becomes increasingly lopsided thanks to the growing dominance of the likes of Nvidia Corp. and Apple Inc.

Players of all stripes are being forced to adapt as the ownership of the largest tech shares in many portfolios starts to push against regulatory limits. And the pressure is building for the two index overlords, whose products are tracked by a combined $35 trillion.

The proposals offer fresh ammunition for critics of the passive-investing boom, who have long pointed out such strategies are more active than they appear. Any adjustments in an index reveal the hidden human hands behind the benchmarks.

“Most investors may not realize that there is some degree of activeness even in what we consider passive strategies,” said Antti Petajisto, head of equities at Brooklyn Investment Group.

Russell’s consultation, which is about capping the weighting of the largest members of its widely followed US growth and value gauges, is open until Aug. 30, with no time frame set for implementation.

S&P’s consultation — focused on a new approach to restrain companies in a family of sector measures — ends Friday, with the changes scheduled to take effect on Sept. 23 if they are adopted.

Behind the proposals are longstanding rules for regulated investment companies that limit any single security to 25% of a portfolio and the aggregate weight of the largest holdings — those with a 5% representation or greater — to 50%. In the industry it’s often dubbed 25/5/50.

Established to safeguard investors from over-exposure to too few names, the restrictions can be punishing in the modern market where companies such as Apple and Nvidia keep getting bigger.

Last month, the top 10 constituents of the Russell 1000 Index — which are mainly tech stocks — comprised 34% of the gauge. While that’s not yet testing 25/5/50, it’s a level of concentration unseen in the benchmark’s 45-year history.