What you are talking about are precisely the aggregate benefits to the markets I mentioned, liquidity and easy risk management.<p>That the markets provide those behaviors is what makes them valuable but the actual trades that make up those aggregates, your selling of shares when you need a car to someone else is zero sum.  Either you would make more by holding or you wouldn&#x27;t.<p>That something other than that is more important to you indicates that you are in the market for a middle man to bridge that time gap and buy some of the risk from you.  Your time horizon is from share purchase to &quot;need money for car&quot;, not from share purchase to &quot;optimal selling point&quot;.  The service you take advantage of when you bridge that gap is provided by the aggregate work of many zero sum interactions between speculative participants like market makers and &quot;investors&quot; like your self.