How Trending ranking works
The one people miss: trending is momentum, not volume — purchases this window minus the previous equal window, so a fast riser can beat a bigger but flat seller.
Trending ranks by momentum, not total volume. It compares this window against the previous equal window and scores the difference — so a product accelerating from a low base can out-rank a bigger seller that’s flat or fading. Only rising products qualify.
1. The collection, unranked
A normal collection page. The order is whatever the catalog lists — the best performers could be buried on the second row where few shoppers scroll.
2. The ranking engine scores it
The engine takes each product’s purchases in two adjacent equal windows — a count of checkouts containing the product, not units — and subtracts: recent − prior. A big positive delta means it’s accelerating. Products that are flat or declining score ≤ 0 and are dropped entirely — trending only ever shows what’s on the way up. Both windows snap to whole days in UTC, so an hours-based window counts as a single day.
3. The front row gets discovered
The strongest products now fill the front row — the slots that get the most views and clicks. That’s the payoff: ranking turns your best products into the ones shoppers see first. Trending is the one rule that never tops itself up: if only four products are rising, you get four — padding a “rising” collection with flat all-time sellers would say the opposite of what the rule is for.