Bitcoin options have tilted toward calls, with Glassnode reporting negative skew as spot momentum cooled. The pricing shift points to relatively richer upside exposure, without establishing fresh call buying. For related coverage, see Metaplanet raises $62 million to buy Bitcoin.

Bitcoin’s 25-delta skew crossed from positive to negative, CryptoSlate reported, citing Glassnode. The original September 8, 2026 Glassnode update includes an Options Delta Skew chart confirming the negative endpoint.

Bitcoin options skew turns negative as calls gain favor

What the reported shift shows

CryptoSlate’s skew comparison describes a change in relative option pricing, not measured call purchases. The available evidence does not identify executed call-buy volume or net new call positions, so “calls gain favor” remains a pricing observation. For related coverage, see Strive Buys $109 Million in Bitcoin.

How 25-delta skew is measured

25-delta skew compares implied volatility for comparable calls and puts with the same expiry, matching the put’s absolute delta. Put implied volatility minus call implied volatility turns negative when calls carry higher implied volatility; reversing that calculation reverses the sign.

CryptoSlate supplies the call-favoring sign interpretation, but the readable primary evidence does not confirm the formula, tenor, sampled venues or comparison endpoints. That missing expiry detail matters when putting the signal beside Bitcoin and Ether options-expiry coverage.

What call-favoring skew suggests about Bitcoin sentiment

Why richer calls can suggest upside interest

The reported negative skew is consistent with interest in upside exposure, although cheaper puts can also move the spread. It does not identify who initiated trades or whether positions express a directional view, hedge or spread.

US spot Bitcoin ETF net inflows reached $681.2 million in the latest reported weekly observation, versus $247.8 million previously, per CryptoSlate; exact window endpoints were not supplied. Those aggregate flows provide context alongside iShares Bitcoin Trust inflow coverage, but do not identify the participants behind the options repricing.

Why negative skew does not guarantee a rally

Spot cumulative volume delta remained negative at −$29.6 million, compared with −$84.9 million previously, per CryptoSlate. The improvement still leaves seller-initiated volume ahead of buyer-initiated volume in the reported measure; its exact aggregation windows remain unspecified.

That negative spot CVD complicates the upside reading from options. Glassnode described building capital inflows, ETF demand and futures leverage alongside cooling spot momentum; its reference to a negative volatility spread concerns a separate indicator.

Bitcoin holds near $79.1k after a flat week.

Capital inflows, ETF demand and futures leverage all build, while cooling spot momentum and a deeply negative volatility spread keep the market finely balanced.

Read this week’s Market Pulse👇https://t.co/gT1UVfvXqu pic.twitter.com/qRT30HDzsD

— glassnode (@glassnode) September 8, 2026

What would confirm a broader shift toward Bitcoin calls?

Check persistence across expiries

The reported negative skew endpoint needs follow-through in comparable observations and across expiries before it supports a broader conclusion. Cross-expiry persistence has not been established by the available evidence.

Compare pricing with trading activity

To test the reported skew shift, watch call and put volume, changes in open interest, and signed trade flows alongside overall implied volatility and spot prices. Volume and open interest alone cannot distinguish buying from selling.

Over the next trading sessions, watch ETF flow updates and whether spot selling eases, alongside the price response around Glassnode’s $79,100 reference level. That connects the options signal with Bitcoin’s price response to stronger ETF buying; the reference is a historical observation, not verified support or resistance.