A GRAT is an arbitrage against the US gift tax: you freeze the gift-tax value of an asset against the IRS section 7520 hurdle rate and let the excess appreciation pass outside your estate. Canada has no gift tax for that structure to bite on. It taxes a deemed disposition at fair market value on death instead. The two systems are solving different problems, and importing the solution to one into the other produces nothing.

The Canadian instrument aimed at the same objective is the estate freeze described above — but it is not a GRAT, the economics differ, and it drags in the trust’s 21-year deemed disposition and the attribution rules in sections 74.4 and 75(2). Those are not footnotes; they are the parts that go wrong.