If everyone is just doing passive investment, there's no real price discovery, it's just valuable companies getting more valuable just because they're already valuable. It also screws with management incentives for the companies when their 'owners' are completely checked out and uninterested in performance.
False! SNAP has been explicitly excluded from the S&P500 index for exactly this reason[0]. I'm not sure if "whole market" passive funds would include it or not. At the very least VTI has 0.03% of assets in SNAP[1]. Not much to worry about.
Yes, and as I said the S&P500 index excludes companies like Snapchat with the founder-has-most-votes trick. I suppose the real issue here is how much money goes into which indices, and which ones exclude companies like these.
