Vol surface skew is asymmetric by default in crypto. Puts trade at higher IV than calls because crashes happen faster and are remembered longer. Most published skew metrics — the 25-delta risk reversal being standard — focus on the difference, with negative readings being the norm.

What gets less attention: when the right tail (out-of-the-money calls) gets bid, the read on positioning is qualitatively different from when the left tail (OOM puts) is bid. Worth being explicit about the difference.

The standard story

When 25-delta risk reversal moves more negative (puts more expensive than calls):

  • Aggregate market is hedging or fearing downside.
  • Dealer gamma typically becomes shorter as they absorb put demand.
  • Often correlates with realized vol picking up in subsequent weeks.

This pattern is well-known and well-traded.

What right-tail bidding actually means

When 25-delta risk reversal moves less negative or briefly positive (calls bid up relative to puts):

Case 1: Speculative call buying. Retail-driven, usually concentrated in front-month, often follows a sharp upward move that drew attention. Short-lived. Resolves in 1-2 weeks as the call premium decays.

Case 2: Structural buyer presence. A large fund or treasury buying upside exposure systematically. Persistent over weeks. Concentrated at specific strikes. Usually involves longer-dated tenors.

Case 3: Convexity hedging. Dealers or funds covering short call positions or hedging crypto-equity correlation positions. Mechanical, not directional.

The three cases look similar in the headline skew number. They differentiate on tenor, strike concentration, and persistence.

How to read which is happening

Speculative case markers:

  • Bid concentrated in front-month (under 14 days)
  • Bid concentrated at specific strikes 5-15% OTM
  • Open interest at the bid strikes grows then collapses within two weeks
  • Typically follows a 10%+ price move in the prior week

Structural case markers:

  • Bid persistent across multiple expirations
  • Bid concentrated at strikes 20-40% OTM
  • Open interest grows steadily over weeks without collapse
  • No clear preceding price catalyst

Convexity hedge markers:

  • Bid coincides with movement in underlying ETH/BTC ratio or correlation positioning
  • Bid concentrated at deep OTM (>30%)
  • Often paired with put activity at similar strikes (delta-neutral)
  • Typically funds-driven, may appear in block trade data

Current snapshot — BTC

As of Friday close:

  • 7-day BTC risk reversal: -2.8 (light put premium, near trailing average)
  • 30-day: -1.4 (minimal put premium)
  • 90-day: +0.4 (slight call premium)
  • 180-day: +1.8 (meaningful call premium)

The 180-day call bid is the interesting print. Strike concentration is at 100-110K and 130K levels. Open interest at these strikes has been building steadily for six weeks. This looks like structural case — long-dated upside positioning, persistent, deeper OTM.

Translation: someone (or several someones) with size is positioning for material BTC upside on a multi-quarter horizon and is willing to pay vol premium for the optionality.

Current snapshot — ETH

As of Friday close:

  • 7-day ETH risk reversal: -3.6
  • 30-day: -2.1
  • 90-day: +0.6
  • 180-day: +0.2

ETH structural call bid is far less pronounced than BTC at the long tenor. Reflects the underlying spot performance gap (ETH/BTC at multi-year lows) and the more uncertain forward fundamentals (upgrade execution, staking economics).

What this matters for

If you're sizing systematic vol-selling positions, the structural right-tail bid at 180-day BTC means selling those long-dated calls has hidden risk — there's a real buyer with conviction on the other side. Selling premium that someone is buying for fundamental reasons rather than speculation has worse historical PnL than fading speculative front-end bids.

If you're positioning directionally, the persistent structural call bid is a soft positive signal for long BTC over multi-quarter horizons. Soft because positioning data is not predictive in the short term — it's predictive in the sense that meaningful capital believes the upside exists.

Bottom line

Right-tail skew bidding isn't one phenomenon, it's three. The right read depends on tenor, strike, and persistence. Currently BTC long-dated calls are structurally bid; ETH less so. That's information about who's positioning and over what horizon, not a tradeable short-term signal.

Skew tells you who's hedged and who's positioning. Direction reads come from elsewhere. Don't conflate them.