A market where a good fluctuates between profitable and not is not one very attractive to investment.
Playing the video game Victoria 3 has taught me a lot about healthy markets. You have to play both sides of supply and demand to get to the prices you need
This is the most wild thing I've ever read on this website. Pick just about any security and you'll see that buying and selling it over time fluctuates between profitable and not profitable. If something was always profitable everyone would do it and get infinitely rich. Arbitrage wouldn't exist. Economies would shut down.