We all know from the past few years that the stock market is no longer something that can be counted on to rise or trend upward. I suggest the following variant to make the market behave a little more realistically:
Remove one +2 card of each color before the game. Players will still have more incentive to increase stock prices than lower them, but they can now more easily manipulate the market downward.
I tried this variant with three players. The market still trended upwards but not as much as before, it felt more balanced with a slightly more bearish feel to the game.
Been thinking, to make the game more bearish, at the end of the round, you could remove from play the highest value card of each stock from the board when you reshuffle the deck for the next round. That will make it more likely the stocks will be more risky to hold onto in the last round.