I don?t know whether it?s ethical, but I don?t believe it is *possible* to make such a prediction, no matter what system you use. In my opinion, tarot is not about fortune telling - because in order to predict the future, the future must be fixed, predetermined. But the future is in constant flux, it is changed by our actions in the present.
Therefore, when I read the cards, my attention is not directed at the future, but at the present; I seek to get a better grasp of *all* *current* factors of a situation, so that I can make more informed choices. The cards that appear for future trends are exactly that: trends, that will change with the changes I make in my approach.
Actually it is the same process as in every decision: you weigh all the factors and then decide. The Tarot helps you to widen your perspective, to take things into account that you would normally have overlooked or suppressed.
As for the stock market - I think that?s an especially dynamic area of life, one that is subject to so many different influencing factors that it is virtually impossible to make a prediction, especially with Tarot. I know that there are astrologers who specialize in this field, but I don?t know how accurate they are.