RE:How Much Would You Pay In TaxesNeed more info to answer that question. Do you mean in income? By a stock going up?
If you mean income, where do you live? That is the main driver of tax rate.
If you are talking about making $1m on the stock market, it depends where you have the stock. If you are in Canada and have your stock in a TFSA you pay 0 tax. If you have it in an investing account then the any growth (once you sell it) is considered income and gets claimed on your taxes as such. So the amount of tax you pay on it would depend on your overall income. Clear as mud?