Passive investments like index funds allow you to buy some ownership of a productive investment vehicle (public companies usually, or rental properties through

Passive investments like index funds allow you to buy some ownership of a productive investment vehicle (public companies usually, or rental properties through REITs), an in exchange you collect rent on that vehicle in proportion to earnings and your share of ownership, for all eternity. It's extractive in that you are literally bidding up ownership of a rent-seeking vehicle, rather than creating any new value at all. In theory you might say bidding up asset values creates something like "potential energy" for productive investment: if an entrepreneur (or venture capitalist to-be) wants to liquidate stock to use as capital for starting a new company, inflated asset values would then contribute to a larger pool of capital for that entrepreneur. Still, I argue that's a stretch. The existence of extractive investment vehicles are the main motivation for capital to invest in new value, yet their continued existence for all eternity leads to an entrenchment of wealth that may threaten the entire system. This is what Marx is all about (although he seems to presuppose a revolution is the end result, rather than say a wealth tax like Bernie / Liz would promote).