BTC CME Gap – detector & single signals

# BTC CME Gap — Detector & Single Signals (Pine v5)

**What it does**
This indicator finds the **weekend gap** on **CME Bitcoin futures** and turns it into a clean, tradable object:

* Draws a **gap zone** (Friday close ↔ Monday open) as a right-extending box.
* Fires **one-time signals** per gap:

* **ENTER** – first touch of the gap zone by price.
* **FILL** – gap is considered filled when price tags **Friday’s close**.

It works on any BTC chart (spot or futures). The gap itself is calculated from **CME\:BTC1!** daily data.

---

## How it works

1. Pulls **daily** `open`/`close` from `CME:BTC1!` (`request.security`, no lookahead).
2. On **Monday**, compares Monday **open** with previous **Friday close**:

* If different → a **gap** exists.
3. Defines the zone:

* `gapTop = max(MonOpen, FriClose)`
* `gapBot = min(MonOpen, FriClose)`
4. Renders a box + boundary lines, **extending right** until price action resolves it.
5. Signals:

* **ENTER**: the first bar that **enters** the gap zone.
* **FILL**: first bar that **touches Friday close** (gap completion).
6. Each new Monday gap **replaces** the previous box and signals.

---

## Inputs

* **CME symbol** (default `CME:BTC1!`)
* **Gap timeframe** (default `D`)
* **Colors** for the box and edges

---

## Plot & Signals

* **Box** = visual gap zone (transparent fill, outlined).
* **ENTER** = triangle up below bar.
* **FILL** = triangle down above bar.
* Optional label prints **Top / Bottom / Fill** levels.

---

## Notes on behavior

* Uses `barmerge.lookahead_off` and daily aggregation, so the gap definition **does not repaint** once Monday’s daily bar is confirmed.
* Signals are **single-shot** per gap (no clutter).
* Works on any chart timeframe; the gap logic always references **CME daily**.

---

## Practical use

* Track obvious **“magnets”** for mean-reversion, stop-runs, or liquidity grabs.
* Combine with your higher-timeframe bias (e.g., **1D trend filter**) and execution on **4H/1H**.
* Typical outcomes: quick Monday fill, staged fill after partial rejection, or delayed fill during later consolidation.

---

## Customization ideas

* Add `alertcondition(enterSignal, …)` / `alertcondition(fillSignal, …)` for automation.
* Gate trades with trend filters (EMA/SMA, Kernel regression, ADX) or session tools (VWAP/POC).
* Persist multiple historical gap boxes if you want to track **unfilled** gaps.

---

**Credits**: Built for BTC CME weekend gaps; minimal, publication-ready visualization with single-event signals to keep charts clean.