Roundhill COST WeeklyPay ETF (COSW) IV/HV History
Comparing implied volatility to historical (realized) volatility reveals whether options are priced rich or cheap relative to actual price movement. Persistent gaps can signal trading opportunities.
Roundhill COST WeeklyPay ETF (COSW) operates in the Financial Services sector, specifically the Asset Management industry, with a market capitalization near $13.0M, listed on CBOE, carrying a beta of 0.34 to the broader market. COSW aims to combine weekly income and modest enhanced exposure to the weekly price performance of COST stock. public since 2025-10-23.
Snapshot as of May 28, 2026.
- Spot Price
- $44.48
- ATM IV
- 21.7%
- HV 20-Day
- 31.3%
- HV 60-Day
- 27.5%
As of May 28, 2026, Roundhill COST WeeklyPay ETF (COSW) ATM implied volatility is 21.7%. 20-day realized volatility is 31.3%, producing an IV-HV spread of -9.6 vol points. Realized volatility currently exceeds implied, an inversion that can signal a pending IV expansion.
How COSW iv/hv history Data Feeds Strategy Selection
Strategy selection on Roundhill COST WeeklyPay ETF options does not derive from any single metric in isolation. The iv/hv history view above sits inside a broader read: ATM IV currently sits at 21.7% and dealer gamma exposure is positive, so dealer hedging is mechanically mean-reverting. Combine the iv/hv history data here with the volatility-skew surface, dealer-gamma exposure, max-pain level, and upcoming-events calendar to build a positioning thesis. Risk-defined structures (credit spreads, debit spreads, iron condors) are usually safer than naked positions while the regime is uncertain; the data on this page anchors the inputs but does not by itself constitute a trade thesis.
How to read the COSW IV vs HV chart
The dual-line chart above tracks ATM implied volatility (forward-looking, what the chain is pricing) against 20-day realized historical volatility (backward-looking, what actually happened). ATM IV currently prints at 21.7%, against 31.3% realized over the trailing 20 trading days. Implied is currently below realized by 9.6 vol points, an inverted regime where premium buyers are underpaying for the move - rare and often a setup for IV expansion. Persistent IV-above-HV is the variance-risk-premium-positive state typical of equity markets; persistent IV-below-HV is rare and usually marks underpriced vol that often expands.
COSW IV/HV regimes and trade selection
Using COSW vol history alongside the term structure
The IV/HV gap on this page captures the level of premium; the term-structure slope on the volatility page captures its shape across expirations. Contango (positive slope 0.170) is the resting state - longer-dated IV trades above near-dated IV because long-dated cycles include uncertain macro states. Pair the rank read with the slope read with the event calendar to choose the right tenor for the structure.
COSW IV/HV signal in volatility-cycle context
Equity-vol cycles tend to compress and expand on multi-month timeframes: a typical sequence runs low-IV-rank consolidation (months of flat tape, decaying premium) into a vol-expansion catalyst (earnings miss, macro shock, regime change) into elevated-IV-rank stress (premiums fat, dispersion high) back to mean-reverting compression. The ratio of HV-20 (31.3%) to HV-60 (27.5%) gives a second cycle indicator: when 20-day exceeds 60-day, recent realization is running hotter than the trailing-quarter average - typically a sign that recent days have already started expanding vol regardless of where IV rank prints. Use the time series above to spot inflection points: meaningful IV/HV gap closures and openings tend to precede regime shifts by a few sessions.
Learn how implied vs realized volatility is reported and how to read the data →
Daily ATM implied volatility and 20-day realized (historical) volatility for COSW over the last ~31 trading days. The IV-HV gap measures the variance risk premium - when IV trades persistently above realized HV, premium-sellers earn the spread; when IV dips below HV, vol is structurally underpriced.
Most recent 15 trading days (descending). Older history appears in the chart above.
| Date | ATM IV | HV 20d | HV 60d | IV Rank |
|---|---|---|---|---|
| May 28, 2026 | 21.7% | 31.3% | 27.5% | - |
| May 26, 2026 | 41.4% | 31.2% | 27.6% | - |
| May 22, 2026 | 32.7% | 28.3% | 27.3% | - |
| May 21, 2026 | 30.0% | 27.3% | 26.9% | - |
| May 20, 2026 | 33.1% | 24.5% | 26.9% | - |
| May 19, 2026 | 41.4% | 23.5% | 26.7% | - |
| May 18, 2026 | 26.9% | 35.2% | 26.5% | - |
| May 15, 2026 | 26.3% | 35.0% | 26.1% | - |
| May 14, 2026 | 36.4% | 34.9% | 26.0% | - |
| May 12, 2026 | 19.3% | 34.2% | 25.7% | - |
| May 11, 2026 | 28.0% | 32.7% | 25.7% | - |
| May 8, 2026 | 41.5% | 32.3% | 25.6% | - |
| May 7, 2026 | 37.5% | 32.3% | 25.6% | - |
| May 6, 2026 | 38.3% | 32.3% | 25.5% | - |
| May 5, 2026 | 41.5% | 31.1% | 25.2% | - |
Frequently asked COSW iv/hv history questions
- Is COSW options pricing rich or cheap right now?
- As of May 28, 2026, Roundhill COST WeeklyPay ETF (COSW) ATM IV is 21.7% against 20-day realized volatility of 31.3%. Realized volatility currently exceeds implied: an inversion of the typical equity volatility risk premium that often precedes IV expansion.
- What is the COSW variance risk premium?
- The variance risk premium is the persistent gap between implied and subsequently realized volatility. In equity markets it averages positive because option sellers demand compensation for bearing variance shocks. COSW is currently pricing inverted to the historical pattern, which is one input to whether short-vol or long-vol structures carry their typical edge.
- What does COSW IV rank mean for strategy selection?
- IV rank normalizes the current ATM IV to its 1-year range: 0% is the low, 100% is the high. COSW's current rank signals where current pricing sits in its own 1-year history. High-rank regimes typically favor premium-selling structures (credit spreads, condors, covered calls); low-rank regimes typically favor premium-buying or long-volatility structures.