Bitcoin options used to be one market. If you wanted to know what volatility was pricing, you looked at Deribit, maybe glanced at a couple of smaller offshore venues, and that was the whole picture. The flow was crypto-native. Miners hedging production, funds punting on calls, market makers who lived and died by the perp basis. Then options listed on the US spot ETFs, and a second surface appeared, cleared through a regulated clearinghouse, quoted during New York hours, and traded by people whose day job is equity derivatives. I have spent a lot of time watching how those two surfaces talk to each other, and the short version is that the structure of bitcoin volatility changed in ways that show up on the chart even if you never touch an option.
The mechanism is old and boring, which is why I trust it. It is the same dealer hedging machinery that equity vol traders have obsessed over for decades. What changed is that bitcoin now carries enough listed, regulated options open interest for that machinery to leave fingerprints on spot.
The hedging loop, briefly
When a dealer sells you a call, they do not want your directional bet. They hedge it by buying some of the underlying, and as price moves they adjust. The adjustment is where all the interesting effects come from. A dealer who is net long options is long gamma, and staying delta-neutral forces them to sell as price rises and buy as it falls. That is a stabilizing flow, it leans against every move. A dealer who is net short options is short gamma, and the same discipline forces them to buy strength and sell weakness, which pours fuel on whatever the market was already doing.
Offshore market makers have always done this too, hedging in perps and spot. But the offshore books were comparatively balanced, speculative two-way flow without a large structural seller or buyer dominating one side. The ETF options brought two flows that push dealer books in predictable directions. Covered call funds, which sell upside on a schedule, and a retail options crowd trading through ordinary brokerage accounts, which tends to buy short-dated calls in bursts. Once you know which of those is dominating, you know roughly which way the hedging wind blows.
Where the upside vol went
The covered call machine deserves its own section because it is the most persistent flow in the system. Income funds built on the spot bitcoin ETFs sell calls systematically, typically on a monthly or weekly cycle, regardless of any view on price, because generating option premium is the product. Dealers take the other side and accumulate long call inventory, which means long gamma concentrated above the market. As price rallies toward the overwritten strikes, dealer hedging sells into the rally. The result is that rallies inside the overwritten zone tend to grind rather than rip, and realized upside volatility compresses relative to what the old offshore-only market would have delivered.
This matters more for bitcoin than it would for most assets because bitcoin historically carried call skew. Upside options often traded richer than downside because the marginal buyer was speculating on a melt-up, which is the opposite of equity index skew. Systematic overwriting leans directly against that old structure. When the overwriting flow is heavy, upside implied vol gets cheap relative to its own history, and there is a certain comedy in an asset famous for face-melting rallies acquiring a shareholder class that is paid specifically to sell those rallies forward.
Pinning is the other visible effect. Into a large monthly expiration, if open interest clusters at a strike and dealers are long gamma there, their hedging keeps nudging price back toward it. Sell the pops above, buy the dips below, over and over, until expiry releases the position. It shows up as a bias rather than a rule, but I have watched spot orbit a round number into an expiry Friday enough times that the expiration calendar now sits permanently on my desk.
Two surfaces, one asset
The ETF options and the offshore options price the same asset through different plumbing. ETF options are American-style, exercise into ETF shares, and trade only during US market hours. The big offshore contracts are European-style, cash-settled, and sit on an underlying that trades continuously. Arbitrage keeps the two surfaces roughly aligned, but the frictions are real and the differences are informative.
The cleanest example is the weekend. Bitcoin trades through Saturday and Sunday. The ETF and its options do not. A dealer hedging an ETF options book can use offshore perps or CME futures to stay covered through the weekend, but not every desk can or will, so gap risk around the Friday close and the Monday open gets priced into the listed surface in a way the offshore surface handles continuously. Around big scheduled weekend risk you can watch the two surfaces openly disagree.
Those disagreements are worth reading. When ETF option implied vol trades rich against comparable offshore tenors, US-hours flow is demanding protection or leverage faster than crypto-native supply is arriving. When the offshore surface leads, the impulse is coming from the crypto-native side. Neither is a trade by itself, but the direction of the gap tells you where the pressure originates, and I have found it more honest than most sentiment indicators.
Reading positioning as a signal
My working process, which fits on an index card:
- Pull open interest by strike and expiry on the largest ETF options chain and mark the clusters. Strikes with heavy open interest near spot are the ones dealer hedging will defend or pin.
- Ask who initiated the position. Persistent overwriting from income funds means dealers are long those calls and the zone dampens moves. A burst of retail call buying flips the sign, dealers get short gamma, and rallies can accelerate instead of stalling.
- Watch the skew on both venues, upside versus downside at comparable deltas. Skew flattening while price rises usually means overwriting supply is soaking up the speculative bid.
- Keep the expiration calendar visible. Behavior often changes in the first session after a large expiry rolls off, because the gamma that was shaping the tape simply disappears.
- Compare ETF implied vol to offshore implied vol at the same tenor and note which side is leading.
The failure mode is the important part. Long gamma dampening trains you to fade moves, because for weeks at a time fading works. Then a genuine catalyst arrives, or expiry wipes the stabilizing position off the board, or the flow flips to short gamma, and the same reflex that printed small steady wins gives it all back in a session. Positioning describes how the market behaves at rest. Once real news arrives that map stops working, and mixing those two regimes up is the standard way people lose money with this framework.
None of this requires trading a single option. I mostly use it as context for spot and futures decisions. If bitcoin has gone strangely quiet and started drifting toward a round number a few days before a monthly expiration, my first assumption is that somebody's hedging is absorbing the flow, and the practical questions are whose it is, which way their book is leaning, and what date it rolls off.