His sell action _right now_ signals that he thinks it has lost value. What happens after that with the stock is independent of his opinion there. Sure, the stock may go up in the short-term because of all of this, but his action now agrees with his sentiment that they're doing something harmful that has effects _in the future_.
What happens with the stock price isn't just reading tea leaves, but totally unimportant to the discussion. Whether you think a stock is going to go up or down isn't the only (and at the institutional level not even the most important) reason that you buy or sell a stock.
I think there is really no connection between moving your taxes abroad and how well the stock will fare. Maybe it will go up, maybe it will go down, but that tax optimization move will have very little impact on that in the long run.
What Cuban is doing isn't a financial move but a principle one. He's unhappy with the company's decision and that's how he shows it.
His sell action _right now_ signals that he thinks it has lost value. What happens after that with the stock is independent of his opinion there. Sure, the stock may go up in the short-term because of all of this, but his action now agrees with his sentiment that they're doing something harmful that has effects _in the future_.
What happens with the stock price isn't just reading tea leaves, but totally unimportant to the discussion. Whether you think a stock is going to go up or down isn't the only (and at the institutional level not even the most important) reason that you buy or sell a stock.