Exactly, which is why taking a position in this type of stock can be really advantageous in your TFSA because if it does blow up, then you don't have to pay the tax on the gains.
Contributing more than 31k would be moronic as there are massive penalties and you have to be careful with taking out or putting into your TFSA as the rules are quite clear but quite strict as well. Apparently lots of people don't understand them and pay handsomly.