RSU's become a taxable event when they are vested. RVX tends to not tell us when they will be vested. When they are vested, their value is set at the price at that time and the value is treated as money paid to them like a bonus or pay so taxed at their full tax rate. A lot of companies might vest them in portions over years and each portion becomes taxable when vested. Many of RVX's in the past have been vested almost right away but as you can see, there are some that haven't as are still carried as RSU's from the past. The norm is for enough shares to be sold to raise the cash to pay the tax to CRA with the remainder being issued common shares to add up to the total that were RSU's. If you were issued 1 million RSU's and then vested while you had a tax rate of 40%, you would receive 600,000 shares and 400,000 would be sold to raise the cash for taxes.