Thanks to all who participated in this.

The rule preventing selling losers & buying them right back to offset capital gain makes sense & clever from CRA perspective. In fact I have done that a few times in the past..

But CRA being ok with selling at the high & buying lower, so to add more $s to capital gain makes sense as well, as CRA collects more money.

The other question is whether it would make sense to sell at all the shares of a company that is expected to go much higher from the time one is thinking about selling & rebuking lower?

Or it would make more sense to just hold longer?