Not just stock holdings. Any investments. Except for your primary residence, if you sell it before leaving. So e.g. you're not safe just because you didn't own stock and instead created a real estate investment empire :) If you keep your primary residence and rent it out for example (presumably because you do want to come back and retire in Canada?), then capital gains will accrue from the date you leave Canada.
Fictitious sale = deemed disposition. Same thing. If you can't pay the tax from cash you have lying around you will have to actually sell some of the investments.
Now I do get that selling a business might not be as easy as selling (part of) a liquid stock. But take the real estate example again. Selling your real estate empire seems much harder than selling some of your NVDA shares to pay the tax. If you aren't prepared to sell your business though and you want to hold onto it, why would the government be inclined to believe that you really want to leave and never come back so to speak?
Fictitious sale = deemed disposition. Same thing. If you can't pay the tax from cash you have lying around you will have to actually sell some of the investments.
Now I do get that selling a business might not be as easy as selling (part of) a liquid stock. But take the real estate example again. Selling your real estate empire seems much harder than selling some of your NVDA shares to pay the tax. If you aren't prepared to sell your business though and you want to hold onto it, why would the government be inclined to believe that you really want to leave and never come back so to speak?