Start from the job of the strike
If you want high gamma and a clean vol expression, ATM (or slightly OTM) is usually the liquid heart of the board. If you want a hedge that already behaves like short or long delta, ITM options carry more intrinsic and more delta, and cost more. If you want convexity with a small premium outlay, OTM options can do that — they also expire worthless often.
Write the job down: hedge a spot stack, buy a rally with defined cash, sell a range, or harvest rich IV. The same underlying supports all four; the strike that fits one job wrecks another.
Moneyness is relative to a reference
ATM is “near the reference,” but the reference might be index, mark, or a futures-implied forward. Crypto books can disagree slightly. Delta is a practical shortcut: ~0.50 calls are near ATM; 0.25 delta is a common wing; 0.10 delta is a far wing with wider markets.
Do not mix inverse and linear deltas or OI as if they were the same units. Convert or compare within one product line first. See the moneyness and inverse-vs-linear guides.
Liquidity is part of the strike
A theoretically perfect strike with a five-dollar-wide market is a bad strike. Look at bid/ask in premium and in vol points, size on the BBO, and open interest. Strike insight on /t/{asset}/strike-insight concentrates OI, greeks, and tape for one expiry/strike so you can see whether anyone actually trades it.
Wings on alt underlyings and far-dated tenors are often decorative. If you cannot exit without wrecking the thesis, you do not have a liquid option — you have a quote.
Walls, GEX, and clustering
Call and put walls mark strikes with unusually large call or put OI (sometimes gamma-weighted). They are focal points for hedging stories, not hard barriers. Max pain is an expiry pinning heuristic, not a magnet you should blindly sell.
If your strike sits on a massive wall, expect noisier dealer-hedging narratives and possibly better two-way flow. If it sits in a hole between walls, expect thinner markets. Use /t/{asset}/gex and /t/{asset}/levels as context, then confirm on the chain.
Structures change the strike decision
Verticals need two strikes: the long leg expresses the view; the short leg finances it and caps payoff. Too-tight width is cheap and tiny; too-wide width is a near-naked option with extra credit. Straddles use ATM; strangles use symmetric or skew-adjusted wings. Risk reversals deliberately pick a put wing versus a call wing because skew is the trade.
Build the shape in Risk lab before you fall in love with a round number. Fees and spread on both legs matter more on cheap OTM wings.
Practice this on OptionsMatch
Open /t/btc/chain, pick an expiry, sort or scan ATM ± a few strikes. Jump to /t/btc/strike-insight for one contract. Check /t/btc/gex for walls. When you know the product, use /venue to see which books list that underlying.
Research only. A strike is not a recommendation.