In the game, when the stocks are low enough, a player can own more than 60% if I understand the rules well enough, but if the stocks move up, to the point where they can only own 60% again, do they retain the 100% shares that they have, or must they sell, even though that would push it back into the ability to own 100% again? How would that work?
Basically you have 2 options, you either
a) Sell stock(s) until you have a maximum of 60% of a single company or..
b) Sell stock(s) so that you end up back to the area that allows you to hold more than 60% of a company's stock.
Forgot about the first opportunity, so if for example having 100% of the stock sold would push the stock above the "hold more than 60%" threshold (and at the end of operating round(s) the stock value is still above the said threshold) you would have to sell (at the next stock round) stock according to a) or b).