Term Structure
How implied volatility varies across expirations
What is Term Structure?
Term Structure Term structure refers to how implied volatility varies across different expiration dates on the same underlying. Plotting IV by days-to-expiration creates the term structure curve — typically upward-sloping in calm markets (longer-dated options have higher IV) and inverted during stress (short-dated IV spikes above long-dated). The shape of the term structure carries information about market sentiment: - **Contango (upward-sloping)**: Normal regime. Short-dated IV is lower than long-dated IV. Markets are calm; the market prices in more uncertainty for the distant future than for the next few weeks. - **Backwardation (downward-sloping or inverted)**: Stress regime. Short-dated IV is higher than long-dated. Markets are pricing in immediate uncertainty — typically during sell-offs, ahead of major events, or after vol spikes. Backwardation tends to mean-revert quickly. - **Humped term structure**: Specific upcoming event drives elevated IV at one expiration (e.g., the expiration immediately after earnings). Common around binary events. VIX term structure (VIX vs VX9D vs VIX3M vs VIX6M) is the most-watched in equity markets. The VIX-to-VIX3M ratio is a popular regime indicator: ratio under 1.0 (VIX < VIX3M) means contango; over 1.0 means backwardation. Historically, sustained backwardation predicts further weakness; rapid backwardation-to-contango transitions often mark short-term bottoms. Term structure has direct trading applications. **Calendar spreads** exploit term-structure mispricing — buy the longer-dated leg, sell the shorter-dated leg. Profits when the front-month IV decays faster than the back-month IV (which it usually does in contango regimes). **Vol-relative-value funds** trade the slope of the term structure across multiple expirations. For options strategies generally, term structure shapes strike selection: - In contango (normal), short-dated premium is relatively cheap. Premium-selling at the front month is less attractive; back-month strategies (45-DTE+) get richer per day of theta. - In backwardation, short-dated premium is rich. Front-month iron condors and credit spreads have structural edge as IV mean-reverts. The VIX-VIX3M spread is a useful real-time monitor. Sudden inversions (e.g., during August 2024 yen unwind, March 2020 COVID, February 2018 Volmageddon) signal regime-change windows that materially alter the math of premium-selling strategies.
Complete Definition
Term structure refers to how implied volatility varies across different expiration dates on the same underlying. Plotting IV by days-to-expiration creates the term structure curve — typically upward-sloping in calm markets (longer-dated options have higher IV) and inverted during stress (short-dated IV spikes above long-dated). The shape of the term structure carries information about market sentiment: - **Contango (upward-sloping)**: Normal regime. Short-dated IV is lower than long-dated IV. Markets are calm; the market prices in more uncertainty for the distant future than for the next few weeks. - **Backwardation (downward-sloping or inverted)**: Stress regime. Short-dated IV is higher than long-dated. Markets are pricing in immediate uncertainty — typically during sell-offs, ahead of major events, or after vol spikes. Backwardation tends to mean-revert quickly. - **Humped term structure**: Specific upcoming event drives elevated IV at one expiration (e.g., the expiration immediately after earnings). Common around binary events. VIX term structure (VIX vs VX9D vs VIX3M vs VIX6M) is the most-watched in equity markets. The VIX-to-VIX3M ratio is a popular regime indicator: ratio under 1.0 (VIX < VIX3M) means contango; over 1.0 means backwardation. Historically, sustained backwardation predicts further weakness; rapid backwardation-to-contango transitions often mark short-term bottoms. Term structure has direct trading applications. **Calendar spreads** exploit term-structure mispricing — buy the longer-dated leg, sell the shorter-dated leg. Profits when the front-month IV decays faster than the back-month IV (which it usually does in contango regimes). **Vol-relative-value funds** trade the slope of the term structure across multiple expirations. For options strategies generally, term structure shapes strike selection: - In contango (normal), short-dated premium is relatively cheap. Premium-selling at the front month is less attractive; back-month strategies (45-DTE+) get richer per day of theta. - In backwardation, short-dated premium is rich. Front-month iron condors and credit spreads have structural edge as IV mean-reverts. The VIX-VIX3M spread is a useful real-time monitor. Sudden inversions (e.g., during August 2024 yen unwind, March 2020 COVID, February 2018 Volmageddon) signal regime-change windows that materially alter the math of premium-selling strategies.
Example
VIX at 18, VIX3M at 22. VIX/VIX3M ratio = 0.82 — solid contango, normal market regime. During August 2024 yen unwind, this ratio briefly spiked to 1.45 (deep backwardation) before reverting to 0.85 within two weeks.
Formula
Related Terms
Frequently Asked Questions
What is volatility term structure?
Term structure is how implied volatility varies across expiration dates on the same underlying. Plotted as IV by days-to-expiration. Typically upward-sloping (contango) in calm markets and inverted (backwardation) during stress.
What's the difference between contango and backwardation in volatility?
Contango means short-dated IV is lower than long-dated IV — the normal regime. Backwardation means short-dated IV is higher than long-dated — typically during sell-offs, ahead of major events, or after vol spikes. Backwardation mean-reverts quickly.
How do I trade term structure?
Calendar spreads exploit term-structure mispricing — buy the longer-dated leg, sell the shorter-dated leg. Profits when the front-month IV decays faster than back-month IV (which it usually does in contango). Vol-relative-value funds trade the slope across multiple expirations.
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