# Range Expansion & Contraction API > The volatility-coiling setups breakout traders hunt, computed live from Yahoo Finance daily OHLC — no key, nothing stored. Markets do not trend or chop at random: tight-range days cluster and precede expansion, and the classic edge — Toby Crabel's NR7 (the narrowest daily range of the last seven), the inside day (a bar wholly inside the prior one) and the outside day (a bar that engulfs it) — is that a coiled spring releases. This API measures the coil and the release. For each instrument it returns today's range as a percentile of its recent range (low = contracted/coiling, high = already expanded), whether today is an NR7, NR4, inside or outside day, the average daily range, and the historical frequency of each setup. Crucially it also returns the follow-through: after an NR7, how often the next day broke the NR7 day's high or low and how often its range expanded — the base rate that tells you whether the coil is worth trading. The asset endpoint returns one instrument's full range profile; the screener endpoint ranks the universe by contraction (most coiled, lowest current range percentile — the breakout candidates) or by realised range. This is the range-contraction / NR7 breakout-setup cut — distinct from the candlestick-pattern API (named reversal/continuation shapes, not range size), the volatility dashboard (level, not the coil), and the gap and price APIs. It is the squeeze before the move. ## Authentication All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys. ```bash curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/rangeexpansion-api/..." ``` ## Pricing - **Free** (Free) — 635 calls/Mo, 2 req/s - **Starter** ($12/Mo) — 13,700 calls/Mo, 6 req/s - **Pro** ($39/Mo) — 77,000 calls/Mo, 16 req/s - **Mega** ($86/Mo) — 450,000 calls/Mo, 40 req/s ## Endpoints ### Screener #### `GET /v1/screener` — Rank the universe by contraction, range or outside-day frequency **Parameters:** - `metric` (query, optional, string) — contraction, range or outside_freq Example: `contraction` - `window` (query, optional, string) — Lookback in trading days (60-1000) Example: `252` - `class` (query, optional, string) — index, sector, commodity, bond, stock or all Example: `all` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/rangeexpansion-api/v1/screener?metric=contraction&window=252&class=all" ``` **Response:** ```json { "data": { "note": "Ranked by contraction over window_days of daily OHLC. current_range_percentile places today's high-low range in its recent distribution: low = contracted/coiling (breakout candidate), high = already expanded. is_nr7 marks the narrowest range of the last seven days. Read fresh per call, nothing cached.", "class": "all", "count": 20, "metric": "contraction", "source": "Yahoo Finance", "results": [ { "name": "Nvidia", "rank": 1, "class": "stock", "is_nr7": false, "symbol": "NVDA", "available": true, "avg_range_pct": 2.82, "is_inside_day": false, "is_outside_day": false, "current_range_pct": 2.99, "outside_day_freq_pct": 15.1, "current_range_percentile": 65.9 }, { "name": "Meta Platforms", "rank": 2, "class": "stock", "is_nr7": false, "symbol": "META", "available": true, "avg_range_pct": 2.38, "is_inside_day": false, "is_outside_day": false, "current_range_pct": 2.67, "outside_day_freq_pct": 8.8, "current_range_percentile": 72.2 }, { "name": "Financials Sec …(truncated, see openapi.json for full schema) ``` ### Asset #### `GET /v1/asset` — Full range profile with NR7/inside/outside flags and NR7 follow-through **Parameters:** - `symbol` (query, required, string) — Universe symbol Example: `SPY` - `window` (query, optional, string) — Lookback in trading days (60-1000) Example: `252` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/rangeexpansion-api/v1/asset?symbol=SPY&window=252" ``` **Response:** ```json { "data": { "name": "S&P 500 ETF", "note": "Daily range = high - low. current_range_percentile is today's range within the window. NR7/NR4 = narrowest range of the last 7/4 days; inside/outside days compare the band to the prior bar. nr7_breakout_rate = share of NR7 days whose next day broke the NR7 high or low (>=5 samples or null). Read fresh per call, nothing cached.", "class": "index", "reads": { "setup": "outside day — range engulfed yesterday's, volatility expanding", "state": "expanded — wide range day, move may be exhausting", "nr7_edge": "after an NR7, the next day broke its high or low 100% of the time historically" }, "today": { "is_nr4": false, "is_nr7": false, "is_inside_day": false, "is_outside_day": true }, "source": "Yahoo Finance", "symbol": "SPY", "window_days": 252, "nr4_freq_pct": 28.9, "nr7_freq_pct": 17.9, "observations": 252, "avg_range_pct": 0.94, "current_range_pct": 2.11, "nr7_follow_samples": 44, "inside_day_freq_pct": 8, "outside_day_freq_pct": 11.2, "nr7_breakout_rate_pct": 100, "nr7_expansion_rate_pct": 75, "current_range_percentile": 97.6 }, "meta": { "timestamp": "2026-06-12T10:34:42.147Z", "request_id": "1b424293-67ef-496f-bc6b-35d247997b01" }, "status": "o …(truncated, see openapi.json for full schema) ``` ### Universe #### `GET /v1/universe` — The universe and its classes **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/rangeexpansion-api/v1/universe" ``` **Response:** ```json { "data": { "note": "The universe the screener ranks — liquid index/sector/commodity/bond ETFs and large-cap stocks. Pass class= to a screener call to rank within one class.", "count": 20, "assets": [ { "name": "S&P 500 ETF", "class": "index", "symbol": "SPY" }, { "name": "Nasdaq 100 ETF", "class": "index", "symbol": "QQQ" }, { "name": "Russell 2000 ETF", "class": "index", "symbol": "IWM" }, { "name": "Dow Jones ETF", "class": "index", "symbol": "DIA" }, { "name": "Technology Sector", "class": "sector", "symbol": "XLK" }, { "name": "Financials Sector", "class": "sector", "symbol": "XLF" }, { "name": "Energy Sector", "class": "sector", "symbol": "XLE" }, { "name": "Gold ETF", "class": "commodity", "symbol": "GLD" }, { "name": "Silver ETF", "class": "commodity", "symbol": "SLV" }, { "n …(truncated, see openapi.json for full schema) ``` ### Meta #### `GET /v1/meta` — Service metadata **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/rangeexpansion-api/v1/meta" ``` **Response:** ```json { "data": { "note": "metric is contraction (default, most coiled first), range or outside_freq. window is 60-1000 trading days (default 252). class filters to index/sector/commodity/bond/stock (default all). NR7 = narrowest daily range of the last 7 days; inside/outside days compare to the prior bar. Read fresh per call, nothing cached.", "source": "Yahoo Finance daily OHLC, live", "classes": [ "index", "sector", "commodity", "bond", "stock" ], "metrics": [ "contraction", "range", "outside_freq" ], "service": "rangeexpansion-api", "endpoints": { "GET /v1/meta": "This document.", "GET /v1/asset": "Full range profile with NR7/inside/outside flags and NR7 follow-through (symbol=SPY, window=252).", "GET /v1/screener": "Rank the universe by contraction, range or outside-day frequency (metric=contraction, window=252, class=all).", "GET /v1/universe": "The universe and its classes." }, "description": "Range expansion & contraction — the volatility-coiling setups breakout traders hunt, live from Yahoo Finance daily OHLC (no key, nothing stored). For each instrument it returns today's range as a percentile of its recent range (low = coiling), whether today is an NR7/NR4, inside or outside day, the average daily range, the frequency of each setup, and the foll …(truncated, see openapi.json for full schema) ``` --- Marketplace page: https://www.oanor.com/api/rangeexpansion-api OpenAPI spec: https://www.oanor.com/api/rangeexpansion-api/openapi.json