My understanding is the committees generally make rules for the indices, and then apply them relatively mechanistically, though they do occasionally change the rules. I think it is hard to totally get rid of this. You need some way to judge that a company’s market cap is actually representative of market trading, as opposed to being manipulated by insiders (like LFIN was). Presumably if the index committee changed it to something absurd the regulator could change their index provider for the next year’s bidding, though you are at risk of small changes that do not meet the threshold for firing.
As a minor technical note gross returns often are (very slightly) higher than the index’s, because the managers can profit from stock lending. This is what allows zero-fee ETFs (though they are also somewhat a marketing ploy).
My understanding is the committees generally make rules for the indices, and then apply them relatively mechanistically, though they do occasionally change the rules. I think it is hard to totally get rid of this. You need some way to judge that a company’s market cap is actually representative of market trading, as opposed to being manipulated by insiders (like LFIN was). Presumably if the index committee changed it to something absurd the regulator could change their index provider for the next year’s bidding, though you are at risk of small changes that do not meet the threshold for firing.
As a minor technical note gross returns often are (very slightly) higher than the index’s, because the managers can profit from stock lending. This is what allows zero-fee ETFs (though they are also somewhat a marketing ploy).