I think its helpful to realize that the S&P 500 is not some static index of companies whose selection has been on auto-pilot but actually a fairly actively managed index whose selection algorithm is continuously being updated and refined. There is a not insignificant human judgement component of how to define the selection/weighting criteria.
In some senses, behind the scenes its likely similar to the Twitter/FB/Netflix algorithm - at some point there is some editorial opinion being inserted via criteria and weighing of those criteria.
"Some years ago Bill Miller, then a well-known Legg Mason portfolio manager with a stellar record of beating the market, noted that the S&P 500’s track record of being very hard to beat suggested that active management can succeed and that the Index Committee were actually good active managers."
In some senses, behind the scenes its likely similar to the Twitter/FB/Netflix algorithm - at some point there is some editorial opinion being inserted via criteria and weighing of those criteria.
"Some years ago Bill Miller, then a well-known Legg Mason portfolio manager with a stellar record of beating the market, noted that the S&P 500’s track record of being very hard to beat suggested that active management can succeed and that the Index Committee were actually good active managers."
https://www.indexologyblog.com/2014/08/07/inside-the-sp-500-...