Indicator Lab

Write custom indicators in a concise array formula language — price arrays H L O C V, data series like MKTCAP / DATE, overloaded operators and 37 built-in functions, computed by a WASM engine and rendered on TradingView lightweight-charts. Try H+L, MA(C,5) or a preset below.

Loading WASM engine…

Symbol

Interval

Bars

Loading WASM indicator engine…

Built-in indicators (click to load)

Formula editorCtrl+Enter to run

Syntax cheat sheet

H L O C V — high / low / open / close / volume arrays (one value per bar of the loaded period)

Data series — extra raw data beyond OHLCV, referenced by name and auto-loaded/aligned to the bars (DATE/TIME are UTC; CoinGecko series are daily and forward-filled on intraday charts):

DATE — Per-bar date as a YYYYMMDD number (UTC), e.g. 20260823.
TIME — Per-bar time as an HHMM number (UTC), e.g. 1430.
MKTCAP — CoinGecko historical market cap (USD). Daily granularity — on intraday charts it is a day-level step.
TVOL — CoinGecko aggregate volume across all exchanges (USD, daily) — unlike V, which is the listed exchange only.

NAME:=expr; intermediate variable · NAME:expr; plotted output (can be referenced by later lines)

+ - * / arithmetic · > < >= <= = == <> != comparisons returning 0/1 · & && AND logical and · | || OR logical or

Plot hints: ,overlay on the price pane · ,stick histogram · ,color=#f0b90b

Comments: { } blocks and // lines; bars without enough history stay blank.

Function reference (0)

KDJ for crypto — live chart, free in your browser

KDJ is the stochastic family's three-line variant popular on Asian exchanges. The raw stochastic value (RSV) places the current close between the 9-bar high and low on a 0–100 scale; K and D are smoothed versions of it, and J = 3K − 2D exaggerates the gap between them to expose momentum extremes.

Because J is an amplified difference, it routinely travels beyond 100 or below 0 — those stretches mark aggressive short-term overbought/oversold conditions. Load the preset on any pair and interval; every line's formula stays visible and editable in the editor, and the whole computation runs locally over real exchange candles.

How it works

Pick any trading pair and an interval from 15 minutes to 1 day.
The preset formula loads into the editor — every line stays visible and editable.
The WASM engine evaluates it locally over up to 1000 real exchange candles.
Results render instantly as price-pane overlays or sub-panes.

Frequently asked questions

What does the J line in KDJ mean?

J is 3K − 2D, a leveraged version of the K−D spread. When J spikes above 100 or plunges below 0, the fast and slow lines have stretched far apart, which many traders read as a short-term overbought or oversold extreme.

How is KDJ different from the classic stochastic?

Both start from the same raw stochastic (RSV), but KDJ adds the J line and uses SMA-style smoothing (SMA(X,3,1) here). The result reacts a bit differently to sharp crypto moves — comparing K/D crosses against RSI on the same chart is a quick way to see which suits your pair.

More indicator lab pages

RSI · MACD · Bollinger Bands · Moving Averages · Volume · Bias · Williams %R · Rate of Change · MA Cross Signals