Strategy reference

CPR — Central Pivot Range (Patearn charting lens) — Canonical Reference

Status: LIVE (descriptive charting lens) · Governing decision(s): (CPR "STRUCTURE" pillar / engine) · (the "CPR Spine" charting overlay) · Reconciled: 2026-07-11 .

Origin: 📚 CLASSIC base (floor-trader pivot-range school) + 🏠 HOUSE multi-degree amplification (the "CPR Spine" ladder · compression-percentile · confluence). See the origins notes.

Charter: the single canonical definition + current-state reference for CPR. Deep design: the cpr strategy design notes. Numbers live in code + the calculations and weights notes; this page never restates a formula's constants — it links.

One-line definition: CPR (Central Pivot Range) is a three-line band — a central Pivot wrapped by a BC/TC envelope — projected from a period's *prior* High/Low/Close and read at several degrees (Daily / Weekly / Monthly / Half-yearly); Patearn renders it as the amber "CPR Spine" behind price and screens on its width/shape as descriptive structure and context, never as a ranked or fundable return signal.

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1. What it is

CPR is a floor-trader pivot construct: from a completed period's H/L/C you derive three horizontal lines — a Pivot (the range's centre) plus two envelope lines, BC (bottom-central) and TC (top-central) — that project onto the *next* period as a support/resistance band. Plotted across consecutive periods the band becomes a stepped ribbon whose two readable properties carry the signal:

• Width — how tight the BC↔TC band is (as a % of the Pivot). A narrow band = a *coiled* market (a large move pending); a wide band = an already-expanded / trending state.
• Shape — the sequence of consecutive bands stepping up, down, or turning (the U / inverted-∩ reversal).

The same logic is read at multiple degrees — Daily, Weekly, Monthly, and (added for the chart ladder) Half-yearly — with only the period changing. In Patearn CPR wears two faces over one shared primitive:

1. The STRUCTURE pillar — a nightly-materialized screening engine (cpr_signals) exposing U/∩ reversals, an *unusually-narrow* compression scanner, cross-timeframe amplification and confluence, surfaced in the screener and at /dash/cpr. This is the 4th Patearn pillar beside Positioning (DVPT), Relative Strength, and Quality — it answers *where price sits in its multi-degree structure, whether that structure just turned, and whether it is coiled*.

2. The "CPR Spine" — a charting overlay that draws that same geometry as an amber ribbon behind price on the /dash/stock chart, as higher-timeframe S/R context for whatever interval you are looking at.

Both faces are descriptive: they frame and select, they do not rank a return edge (see §4).

2. Our variation vs. the standard technique

The standard floor-trader CPR is a single-degree, intraday construct: one day's H/L/C → today's Pivot/BC/TC, used as intraday support/resistance. Patearn's variation departs on four points:

• Multi-degree, end-of-day, not intraday. We compute Daily, Weekly, Monthly (and Half-yearly) CPRs from each period's prior H/L/C and read them together — the "CPR Spine" is a *sequence of bands across time*, not one intraday line. Width and shape are read at every degree.
• Width as a first-class "coil" metric. The band width (normalised by the Pivot) is the narrowness signal: narrower = more coiled = bigger pending move. Both an absolute per-degree width cutoff and a *relative* own-history compression percentile ("unusually narrow for this stock") are exposed — the truer "unusual". (Numbers → §3 / the calculations and weights notesb.)
• Shape as a reversal pattern. Three consecutive same-degree CPRs where each leg is a *clean directional step* (both band lines move the same way) form a U (bullish bottom) or ∩ / inverted-U (bearish top). Strength is graded by how narrow the two recent bands are (R1…R4, today's band the priority).
• The chart-ladder convention (the desk rule). On the Spine overlay, the CPR shown is one degree HIGHER than the chart interval — a daily chart shows the Weekly CPR, weekly → Monthly, monthly → Half-yearly — because higher-degree pivots are the meaningful S/R for the horizon you trade. (Contrast: the *screener* / /dash/cpr reads each timeframe's own same-degree CPRs and their reversals.) The Half-yearly (H) degree exists specifically to serve this ladder.

The combiner across degrees: a faster-timeframe signal is amplified when slower timeframes are also coiled/aligned, with the larger timeframe carrying more weight — surfaced as transparent ★ Structure tiers with a visible per-degree breakdown, never an opaque mega-score. Full model + rank tables: the cpr strategy design notes–§5.

3. How it works (methodology)

The primitive. Each CPR is built from the prior completed period's High/Low/Close: a central Pivot, a BC line, and a TC line mirrored about the Pivot, forming the [BC…TC] band centred on the Pivot. The width% normalises the band by the Pivot. Prices are split/bonus-adjusted first so the band and the current close share one continuous price regime.

→ The exact arithmetic for Pivot / BC / TC / width% is not restated here — it lives in code (the cpr signals code, and the chart_view.cpr_segments transform) and is documented once in the calculations and weights notesb and the metrics glossary (CPR section).

Width interpretation ("coil"). A band is flagged *coiled* when its width% is at/under a per-degree cutoff (Daily is tightest, Half-yearly loosest — a flat cutoff would make wider degrees never qualify). The relative measure (compression percentile vs the stock's own trailing history) is the primary "unusually narrow" sort. The per-degree cutoffs and weights are query-time knobs — geometry/widths are stored, rank/score derived on read — so they can be tuned without re-materialising. Values: the calculations and weights notesb; overlay cutoffs live in chart_view.COIL_PCT.

Multi-timeframe stacking. Latest D/W/M pivots that cluster within a small tolerance merge into a confluence S/R slab (a high-probability magnet, drawn as the "D·W·M" band). regime = the sign of close vs Pivot gives the higher-degree trend context that the amplifier rewards. The cross-TF conviction/★ tier is an *additive, breakdown-visible* score (larger degree weighted more), computed on read. All formulae and weights: the cpr strategy design notes + the calculations and weights notesb.

4. Status, validation & honesty fence

LIVE — and deliberately descriptive. CPR is shipped and running (materialized nightly; drawn on the live chart; screenable), but it is a charting / context / selection lens, not a validated alpha signal:

• No standalone return backtest is recorded for CPR in the strategy ledger. There is no measured, cost-net return edge attributed to CPR reversals or compression. This page does not claim one; if you need a fundable edge, CPR is not it.
• Kept OUT of the cross-pillar Conviction number (which stays Positioning + RS only). CPR surfaces as a *parallel* ★ Structure tier column and a one-click "CPR-confirmed" screener gate — never folded into the ranked composite. Rationale : the composite is itself unvalidated, CPR has no live history, and doctrine is "master each pillar alone, then club."
• Consistent with project doctrine: this is context/selection, not fundable alpha. Treat CPR output as *"where is structure, is it coiled, has it turned"* framing that a human (or another validated pillar) then acts on — not as a buy/sell instruction.

Any future attempt to promote CPR into a ranked/return claim must first clear a leak-free out-of-sample backtest and be recorded in the ledger; until then it stays descriptive.

5. Where it lives (code · routes · DB · timers)

Engine (STRUCTURE pillar):

• the cpr signals code — the timeframe-parameterized nightly materializer. Self-resamples its own split-adjusted D/W/M/H H/L/C bars from bhavcopy_rows (replicates _period_key; no dependency on the held MTF foundation). Computes the CPR primitive + clean-step U/∩ reversal + compression percentile + regime + freshness + confirmed. CLI: --backfill / --recent / --symbol, --timeframe D|W|M|all.
• DB: the cpr_signals table (defined in the db code, additive; stock_signals untouched). PK (symbol, period_end_date, timeframe ∈ D/W/M/H). Stores geometry + widths + pattern/regime/flags; rank, amplification and ★ tier are derived on read (never stored).
• Timer: runs as a leg of the nightly signals chain (the cpr signals code --recent --timeframe all, appended after stock_rs) — no upstream dependency, WAL means it never blocks dashboard reads. It is *not* a standalone systemd timer (unlike the harmonic scanner).

Charting overlay (CPR Spine):

• the cpr overlay code — the /dash/cpr/overlay JSON endpoint (reads cpr_signals, one-degree-higher ladder) + a self-contained SNIPPET that draws the Spine primitive on the existing candle series (window.__wfcandle / window.__wfpc) and injects the CPR chip into the chart's "Strategies" family. Default OFF, opt-in. Draws: regime-tinted BC↔TC band, dashed/solid Pivot core, brighter fill at coil, an amber D·W·M confluence slab, and U/∩ markers on the middle candle (with a ? until confirmed).
• the chart view code — the DB-free transforms the overlay reuses: cpr_segments (rows → stepped segments, sets the coil flag off COIL_PCT) and confluence (clustered-pivot slab). ⚠️ render_stock_chart in this module is DEPRECATED / not live (the live /dash/stock chart is the stock chart code's snippet); only cpr_segments / confluence are wired.

Screener & pages ( surfaces, in the dashboard code):

• The CPR column-group in the screener (g-cpr): D/W/M width% + D·W·M glyph strip + R-rank + ★ Structure tier + Comp%, a group-toggle chip, and the "CPR-confirmed" gate.
• The CPR card in /dash/strategies (top fresh structure setups → links out).
• /dash/cpr — three tabs: Reversals (cross-TF amplified ★ screen), Compression (unusually-narrow CPRs by own-history percentile), EOD Reports (Daily/Weekly/Monthly "what fired", W/M carry a "live for the current period" badge).
• A per-stock CPR panel on /dash/stock (the D·W·M strip + P/BC/TC table + plain-English verdict).
• Read-only rollups also consume cpr_signals via the strategy registry code and the strategist view code; Pat grounds on it via the glossary code / the flows code.

6. Data & provenance

CPR is derived entirely from NSE bhav-copy OHLC (bhavcopy_rows) — a primary/authentic source (Doctrine Guardrail #8, primary-sources-only). No vendor or Screener.in dependency. The engine self-resamples split/bonus-adjusted H/L/C period bars (per-day adjustment factors applied, then aggregated), drops anomalous bars (|daily return| > 0.30), and honours the equity-only allowlist + thin-prior-period skips. Everything is re-derivable from the raw archive; the bhav-copy archive is never normalised away (Doctrine § C).

7. Terminology canon

• CPR (Central Pivot Range) — the three-line band (Pivot + BC/TC) from a prior period's H/L/C. *Disambiguation:* this is a pivot-derived S/R + coil construct, distinct from generic hand-drawn support/resistance and distinct from RS-band (rs_band_pct, a relative-strength position vs Nifty 500 — a different lens entirely).
• Pivot (P) — the central line / band centre. BC / TC — the bottom-central / top-central envelope lines that bound the band. (Arithmetic → linked, not restated.)
• Width% / "coil" — band width as a % of the Pivot; the narrowness metric. Coiled = width at/under its per-degree cutoff. Compression percentile (Comp%) = how narrow the current band is vs the stock's own history (the relative "unusual").
• CPR Spine — the amber ribbon rendering of the band sequence behind price on the stock chart (the charting identity). On the overlay it shows the CPR one degree higher than the chart interval.
• U / ∩ (BULL_U / BEAR_INVU) — the three-CPR reversal shapes (bottom / top), each leg a clean directional step.
• Regime — sign of close vs Pivot (above/below); the higher-degree trend context.
• Confluence — ≥2 of the D/W/M bands overlapping at one price → an S/R slab.
• Narrow vs Wide CPR — narrow = coiled/energy-stored (move pending); wide = already-expanded/trending.
• Degrees — D (Daily) / W (Weekly) / M (Monthly) / H (Half-yearly, added for the chart ladder).

Client-facing definitions live in the metrics glossary (CPR section); internal thresholds/weights in the calculations and weights notesb.

8. Decision & session history

• — CPR "STRUCTURE" pillar (2026-06-19, Session 21). The 4th Patearn strategy shipped end-to-end, no-regression: the cpr_signals engine (D/W/M) + screener CPR column-group + Strategies card + /dash/cpr (Reversals · Compression · EOD Reports) + stock panel. All seven OPEN modelling decisions resolved to the recommended defaults via multiple-choice-with-recommendations (leg = both-lines clean step; rank priority = C0; show both + confirmed; width ÷ Pivot; per-TF cutoffs D 1.0 / W 2.5 / M 5.0%; TF weights D 1 · W 2 · M 3; "unusual" = own-history percentile + absolute knob). CPR kept out of the Conviction number. Local decisions CPR-A1…A7, CPR-B1, CPR-X1/X2 (the cpr strategy design notes). Build log: design doc §16.
• Session 42 — one-chart engine. the stock chart code re-homed the CPR chip into the unified four-family rail; the CPR was NOT re-implemented — it stays owned by the cpr overlay code, and the window.__wfpc/__wfcandle contract is preserved so the Spine keeps working. (the desk is happy with the CPR itself — don't touch it.)
• Healing / price-scale sessions (–). After the dead-zone and price-scale fixes, cpr_signals was re-materialized across D/W/M/H as one of the nightly legs (anchor-CPR sanity checked); no methodology change.

9. Open items / frozen work

• Telegram /cpr — designed but NOT shipped. The design doc §7 lists a Telegram /cpr (+/cpr narrow) surface; no such handler exists in the telegram bot code today. Treat it as an unbuilt design aspiration, not a live command. *(Contradiction flagged — see below.)*
• Full 3C trend-stack screen — only the regime bit (close vs Pivot) is consumed today; the full stack/slope FULL BULL…BEAR screen with stack_age/signal_event is deferred.
• 3D confluence as a chart visualization — only the binary flag / merged slab is used; a richer confluence-zone view is deferred.
• Compression coil-age "freshness" (how long a CPR has stayed coiled) — deferred; reversal days_since_pattern freshness is live.
• CPR × DVPT × RS hybridization (the cpr strategy design notes) — recorded only, do not build without an explicit decision; the §4 score is kept additive so this stays a clean extension.
• Folding CPR (or Quality) into the Conviction composite — deferred pending live history + a leak-free validation; a design-panel decision, not a silent default.
• chart_view.render_stock_chart — DEPRECATED/not live; do not re-wire without a decision (the live chart is the stock chart code).

10. Sources of truth

• Deep design + build log: the cpr strategy design notes (the design of record — §3–§5 model, §13 resolved decisions, §14 local decision log, §16 build log).
• Numbers (internal): the calculations and weights notesb — CPR width knobs + ★ Structure tier weights (code constants remain the single source of truth).
• Definitions (client-facing): the metrics glossary — CPR section (Pivot/BC/TC, Width%, Comp%, U/∩, Rank, Regime, where-it-shows).
• Code: the cpr signals code (engine) · the cpr overlay code (Spine overlay + /dash/cpr/overlay) · the chart view code (cpr_segments / confluence / COIL_PCT) · the db code (cpr_signals table) · the dashboard code (screener group, /dash/cpr, stock panel).

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