Just to be clear, the capital gains exemption applies to sales of shares from a qualified Canadian small business, not all capital gains. Also, on that topic,

Just to be clear, the capital gains exemption applies to sales of shares from a qualified Canadian small business, not all capital gains. Also, on that topic, the Canadian controlled aspect of it can be undone by contracts you have with foreign shareholders, such as VCs. They can own < 50% of your stock but if they're deemed to have control by virtue of an option to acquire more stock or to force a sale, you lose the exemption.