Castle Biosciences, Inc. (CSTL) Volatility Skew
Implied volatility skew shows how IV varies across strike prices for a given expiration. Steeper skews indicate higher demand for downside protection relative to upside speculation.
Castle Biosciences, Inc. (CSTL) operates in the Healthcare sector, specifically the Medical - Diagnostics & Research industry, with a market capitalization near $550.5M, listed on NASDAQ, employing roughly 784 people, carrying a beta of 1.11 to the broader market. Castle Biosciences, Inc. Led by Derek J. Maetzold, public since 2019-07-25.
Snapshot as of May 15, 2026.
- Spot Price
- $19.16
- ATM IV
- 84.5%
- IV Skew 25Δ
- 0.179
- IV Rank
- 18.2%
- IV Percentile
- 83.3%
- Term Structure Slope
- -0.224
As of May 15, 2026, Castle Biosciences, Inc. (CSTL) at-the-money implied volatility is 84.5%. IV rank is 18.2% (where 0% is the 52-week low and 100% is the 52-week high). IV percentile is 83.3%. The 25-delta skew is +0.179: calls carry premium over puts, indicating upside speculation or squeeze risk. High IV rank typically favors premium-selling strategies; low IV rank favors premium-buying.
CSTL Strategy Selection at Current Volatility Levels
For Castle Biosciences, Inc. options at 84.5% ATM IV, low IV rank (18.2%) favors premium-buying or long-vol structures: long calls or puts, debit spreads, calendar spreads, long straddles. The risk: low-rank regimes can persist for months while time decay eats premium-buyers alive. The 25-delta skew tilts to calls, so call-credit spreads or covered-call writes harvest more premium than put-credit spreads of the same width. Pair the vol-rank read with the dealer-gamma view and the upcoming-events calendar to confirm the strategy fits both the structural regime and the path-dependent risk. The variance risk premium - the persistent gap between implied and subsequently realized vol - is positive in equity markets on average; high IV rank typically reflects a stretch where the premium is wider than usual.
Learn how volatility skew is reported and how to read the data →
Frequently asked CSTL volatility skew questions
- What is the current CSTL ATM implied volatility?
- As of May 15, 2026, Castle Biosciences, Inc. (CSTL) at-the-money implied volatility is 84.5%. IV rank is 18.2% on a 0-100% scale anchored to the 1-year IV range. ATM IV is the volatility input that makes a Black-Scholes-equivalent model reproduce the listed at-the-money option prices.
- Is CSTL IV high or low historically?
- IV is subdued relative to its 1-year history, conditions that typically favor premium-buying strategies (long calls, long puts, debit spreads, calendar spreads).
- What does CSTL volatility skew tell options traders?
- Volatility skew is the pattern by which IV varies across strikes for a given expiration. Castle Biosciences, Inc. shows upside-skewed pricing: 25-delta calls trade richer than 25-delta puts, often reflecting upside speculation or squeeze risk. Skew matters for risk-defined strategy selection: when downside puts are rich, put-credit spreads capture more premium; when upside calls are rich, call-credit spreads or covered-call writes harvest more.