CL27 as someone who has worked in the industry you are not...

CL27 as someone who has worked in the industry you are not correcting me, an index fund replicates the return of the index, it does not have to hold all 200 stocks in their respective index weights. Unless that is in their mandate which would be unusual, not saying they dont exist.
Think about it for a minute, how difficult would it be to replicate the index exactly? the last few stocks have such a minute impact on the index, trading costs etc of maintaining these weights in a fluid environment would mean it would be impossible to replicate the return due to these costs.
Thanks for correcting me though, appreciate it.