What a sneaker market index actually is
The market as an index. So do sneakers.
A stock index doesn't track one company. A sneaker index doesn't track one shoe.
A stock index doesn't track one company — it tracks a basket of them, so a single number can tell you whether "the market" moved without checking every ticker individually. Sneaker resale has never really had one. Marketplaces show you a single shoe's price; nobody was answering "is the market, broadly, up or down."
The CYKI 100 is our attempt at that missing number: 100 sneakers, selected to represent the resale market's main categories, rebased to 100 at launch and re-priced daily from real sales. It moves the way an index should — as a chart over time, not a single snapshot — built the same way whether the market that day is up, flat, or down.
It exists because the biggest marketplace to attempt sneaker portfolio tracking discontinued that feature outright, and nobody else stepped in with an index. We publish the method openly rather than asking you to trust a black box.
The index isn't one flat number, either. It's broken into cohorts by category, so a Jordan-heavy rack and a running-shoe-heavy rack can each be read against the slice of the market that actually looks like them, not just the average of everything lumped together.