Why benchmark, not average
Most price headlines quote the average sale price, which is the least reliable of the three common measures. Average moves when the mix of what sold changes, not only when values change. A quiet month at the top end drags the average down even if every individual home held its value perfectly.
The benchmark price is modelled on a typical home with consistent characteristics, so it isolates actual value movement. When benchmark and average disagree, benchmark is usually telling you the truer story.
Calgary is not one market
A citywide figure conceals a great deal. Detached, semi-detached, row and apartment segments routinely move at different rates and occasionally in different directions. So do quadrants, and so do individual communities within a quadrant.
A number that says the city is down 2% tells you very little about a specific bungalow in a specific community — which may be up, flat, or down considerably more. The full market stats page breaks it down by property type and district, and every community page carries its own price trend.
The mix-shift trap catches professionals too: if more condos sell one month and fewer detached homes, the average falls and nothing has actually happened to anyone's home value.