Why a put concentration supports
Where put open interest piles up, dealers who sold those puts carry long gamma below spot: as price falls toward the strike, their hedging buys into the decline — mechanically, indifferent to sentiment. That is the put wall: not a promise, a concentration whose hedging flow leans against approaches.
The crypto asymmetry
Crypto books lean toward calls, so put walls here are typically thinner and lower than their equity cousins — protective-put culture is younger, and much of the downside hedging happens in perps instead. A thin put wall supports less; knowing WHICH kind sits below spot is the difference between a level and a hope.
Expiry resets the floor
With something expiring every day at 08:00 UTC, a put wall’s support has a timestamp: hedges unwind as their strikes expire, and a floor that held all week can simply not exist on the next session’s map. Reading the wall means reading its expiry composition, not just its size.
Reading it
Check the wall’s distance, its size relative to the book, and how much of it dies at the next expiry. A fat, near, long-dated put wall is real structure; a thin one inside a call-heavy book is a line on a chart.