# Half on a Double > End-of-day options-positioning reference levels for US stocks and ETFs. Public results and interpretation; proprietary calculations are not published here. Data through: 2026-10-16 close. Cite the date and canonical URL. These are descriptive model outputs, not live prices or predictions. Missing is not zero. ## Start here - [Public data guide](https://halfonadouble.com/index.md) - [Definitions and limitations](https://halfonadouble.com/methodology.md) - [Daily screens](https://halfonadouble.com/screens.md) - [All current screener results](https://halfonadouble.com/screener-data.md): one dated Markdown file, refreshed with each site publication. - [Level distance rankings](https://halfonadouble.com/rankings/level-distance.md) - [Combined guide and screens](https://halfonadouble.com/llms-full.txt): bounded reading context; excludes ticker history. - [Data access and reuse](https://halfonadouble.com/data.md) - [Learning guides](https://halfonadouble.com/learn.md) ## Machine-readable data - [OpenAPI description](https://halfonadouble.com/openapi.json): stable read-only JSON and CSV interfaces. - [Publication metadata](https://halfonadouble.com/api/v1/series.json): data-through date, methodology and URL templates. - [Ticker inventory](https://halfonadouble.com/api/v1/tickers.json): symbols with canonical pages and Markdown availability. Ticker snapshots use `/stock/SYMBOL.md` and `/api/v1/tickers/SYMBOL.json`. Historical CSV uses `/api/v1/history/SYMBOL.csv`. Complete same-date derived advanced-options analysis, when available, uses `/api/v1/analysis/SYMBOL.json`. Symbols must come from the ticker inventory. Automated personal research is permitted when access is polite; bulk republication, resale and product use require permission. ## Screens - [Call OI growth leads puts (1 session)](https://halfonadouble.com/screens/call-oi-growth-1d.md) - [Call OI growth leads puts (5 sessions)](https://halfonadouble.com/screens/call-oi-growth-5d.md) - [Unusual call open interest accumulation](https://halfonadouble.com/screens/unusual-call-oi-accumulation.md) - [Unusual OI growth shift toward calls](https://halfonadouble.com/screens/unusual-call-oi-growth-shift.md) - [Put OI growth leads calls (1 session)](https://halfonadouble.com/screens/put-oi-growth-1d.md) - [Put OI growth leads calls (5 sessions)](https://halfonadouble.com/screens/put-oi-growth-5d.md) - [Unusual put open interest accumulation](https://halfonadouble.com/screens/unusual-put-oi-accumulation.md) - [Unusual OI growth shift toward puts](https://halfonadouble.com/screens/unusual-put-oi-growth-shift.md) - [Gamma max crosses](https://halfonadouble.com/screens/gamma-max-crosses.md) - [Delta neutral crosses](https://halfonadouble.com/screens/delta-neutral-crosses.md) - [Nearest gamma max](https://halfonadouble.com/screens/nearest-gamma-max.md) - [Most open interest](https://halfonadouble.com/screens/most-open-interest.md) - [Nearest max pain](https://halfonadouble.com/screens/nearest-max-pain.md) - [Gamma exposure extremes](https://halfonadouble.com/screens/gex-extremes.md) - [Call/put contract extremes](https://halfonadouble.com/screens/call-put-contract-extremes.md) - [Put/call open interest extremes](https://halfonadouble.com/screens/put-call-open-interest-extremes.md) - [Open interest surge](https://halfonadouble.com/screens/open-interest-surge.md) - [Unusual open interest accumulation](https://halfonadouble.com/screens/unusual-open-interest-accumulation.md) - [Options catalyst watch](https://halfonadouble.com/screens/options-catalyst-watch.md) - [IV rank extremes](https://halfonadouble.com/screens/iv-rank-extremes.md) - [IV term-structure extremes](https://halfonadouble.com/screens/iv-term-structure-extremes.md) - [Expected-move extremes](https://halfonadouble.com/screens/expected-move-extremes.md) - [ATM straddle-implied move](https://halfonadouble.com/screens/straddle-implied-move.md) - [25-delta risk-reversal extremes](https://halfonadouble.com/screens/risk-reversal-extremes.md) - [Option volume activity](https://halfonadouble.com/screens/option-volume-activity.md) - [Net delta positioning extremes](https://halfonadouble.com/screens/net-delta-positioning.md) - [Modeled dealer-delta extremes](https://halfonadouble.com/screens/dealer-delta-positioning.md) - [Vanna exposure extremes](https://halfonadouble.com/screens/vanna-exposure-extremes.md) - [Charm exposure extremes](https://halfonadouble.com/screens/charm-exposure-extremes.md) - [Volatility smile convexity extremes](https://halfonadouble.com/screens/volatility-smile-convexity.md) - [IV surface dispersion](https://halfonadouble.com/screens/iv-surface-dispersion.md) - [Forecast volatility above implied volatility](https://halfonadouble.com/screens/volatility-forecast-discount.md) - [Historical payoff versus option premium](https://halfonadouble.com/screens/historical-payoff-value.md) - [Breakouts with inexpensive options](https://halfonadouble.com/screens/breakout-with-inexpensive-options.md) - [Historically cheap call and put skew](https://halfonadouble.com/screens/historically-cheap-calls-puts.md) - [IV expansion from a low base](https://halfonadouble.com/screens/iv-expansion-low-base.md) - [Unusual activity without substantial repricing](https://halfonadouble.com/screens/unusual-activity-without-repricing.md) - [Inexpensive forward-volatility windows](https://halfonadouble.com/screens/inexpensive-forward-volatility.md) - [Long-option contract scenario value](https://halfonadouble.com/screens/long-option-scenario-value.md) - [Contract doublers: catalyst discovery](https://halfonadouble.com/screens/contract-doublers-5d.md) ## Rankings - [Gamma max and delta neutral distance rankings](https://halfonadouble.com/rankings/level-distance.md) - [Gamma max: farthest today](https://halfonadouble.com/rankings/gamma-max/farthest.md) - [Gamma max: closest today](https://halfonadouble.com/rankings/gamma-max/closest.md) - [Gamma max: historically farthest](https://halfonadouble.com/rankings/gamma-max/historical-farthest.md) - [Gamma max: historically closest](https://halfonadouble.com/rankings/gamma-max/historical-closest.md) - [Delta neutral: farthest today](https://halfonadouble.com/rankings/delta-neutral/farthest.md) - [Delta neutral: closest today](https://halfonadouble.com/rankings/delta-neutral/closest.md) - [Delta neutral: historically farthest](https://halfonadouble.com/rankings/delta-neutral/historical-farthest.md) - [Delta neutral: historically closest](https://halfonadouble.com/rankings/delta-neutral/historical-closest.md) ## Ticker snapshots 607 full-history ticker pages have a current Markdown snapshot at `/stock/SYMBOL.md`. Use the [ticker inventory](https://halfonadouble.com/api/v1/tickers.json) instead of loading a link for every symbol into context. ## Optional - [Disclaimer](https://halfonadouble.com/disclaimer.md) - [Terms of use](https://halfonadouble.com/terms.md) - [Privacy policy](https://halfonadouble.com/privacy.md)