A roll closes an expiring contract and opens a similar one further out. It is how a position is maintained past its expiry, and with crypto expiries as frequent as they are, it comes up constantly.
What it costs
Two round trips: closing the near leg and opening the far one, each crossing a spread and paying fees. On liquid strikes that is minor. On thin ones it is not, and the cost recurs every time — a position rolled weekly pays it weekly.
Because the cost is charged as execution rather than as a loss, it rarely appears in a trader’s mental accounting. A strategy that looks profitable and rolls frequently should be evaluated with those costs included, at the prices you would actually be filled at.
The decision it disguises
This is the more important half. Rolling is not maintenance — it is a fresh decision to hold the position, made at today’s prices, in today’s conditions.
The honest test is whether you would open this position now if you held nothing. If not, the roll is a way of avoiding closing a trade you have stopped believing in, and the fact that it feels like continuity is precisely what makes it easy.
The volatility you are re-buying
The new leg is priced at current implied volatility, which may be nothing like what the original was bought at. Roll a long option after volatility has risen and you are re-buying the same exposure at a materially higher price.
So the roll is also a vega decision, and reading it needs the term structure rather than just the price of the contract you are leaving.
When it is clearly right
When the original thesis still holds and simply needs more time, and when the structure being rolled into is one you would choose independently. Both conditions, not either — and if the second fails, the trade to make is closing, not rolling.