Which books set a price and which copy it

A small number of operators price independently. Most of the market watches them and follows within seconds, which is why prices move together and look coordinated.

Pricing a market from scratch is expensive — models, data, traders. Copying a respected book is cheap and safe, and it is what the majority of the industry does on most markets.

Some books originate in one sport and copy in another, so the same brand can be sharp on football and derivative on hockey.

What follows from that is less comfortable. The number of brands available suggests far more independent opinion than actually exists, which makes the market look softer than it is.

What to do with it. Learn which books originate in your sport, watch those, and treat everything else as a delayed copy.