"After all, the market is supposed to be useful for organizing long-term investments"
This is a very HN specific way of thinking (and probably obvious given the startup culture here) but it is not a truism. Many, many, many (perhaps most) market participants are not involved in the markets to organize long term investments. They are there to hedge risk (whole classes of exchanges exist nearly solely for this, think commodities markets).
But that is the glory of the markets. You can be a participant who is looking for long term investment, Southwest Airlines can be there to hedge risk, and I can be there to make a dime fast and we can all participate in what seems to be a zero sum game and win.
This is a very HN specific way of thinking (and probably obvious given the startup culture here) but it is not a truism. Many, many, many (perhaps most) market participants are not involved in the markets to organize long term investments. They are there to hedge risk (whole classes of exchanges exist nearly solely for this, think commodities markets).
But that is the glory of the markets. You can be a participant who is looking for long term investment, Southwest Airlines can be there to hedge risk, and I can be there to make a dime fast and we can all participate in what seems to be a zero sum game and win.