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TradeX Chart

Glossary

A comprehensive guide to terminology used in TradeX Chart and financial charting.

A

API (Application Programming Interface)

The set of methods and properties exposed by TradeX Chart for programmatic control and customization.

ATR (Average True Range)

A technical indicator that measures market volatility by calculating the average range between high and low prices over a specified period.

Axis

A reference line used to measure and display data values. TradeX Chart uses:

  • X-Axis (Timeline): Horizontal axis showing time
  • Y-Axis (Scale): Vertical axis showing price or value

B

Bollinger Bands

A volatility indicator consisting of a moving average with upper and lower bands that are standard deviations away from the average.

Buffer

Extra space allocated beyond the visible chart area to enable smooth scrolling and panning. Configured via config.buffer.

Candle

See Candlestick.

Candlestick

A chart element representing price movement over a time period, showing:

  • Open: Opening price
  • High: Highest price
  • Low: Lowest price
  • Close: Closing price
  • Body: Rectangle between open and close
  • Wick/Shadow: Lines extending to high and low

Canvas

The HTML5 <canvas> element used by TradeX Chart for rendering. TradeX uses multiple layered canvases for performance optimization.

CEL (Canvas Extension Layer)

TradeX Chart’s custom canvas layer system for managing multiple rendering layers.

Chart Pane

A distinct section of the chart that can contain price data or indicators. Types include:

  • Primary Pane: Main chart showing price/candlesticks
  • Secondary Pane: Additional panes for indicators (e.g., RSI, MACD)

Config

The configuration object passed to chart.start() that defines chart behavior, appearance, and initial state.

Core

The central component of TradeX Chart that manages state, events, and coordinates all other components.

Cursor

The crosshair or pointer displayed when hovering over the chart, showing precise time and price values.

D

DataSource

The class responsible for managing data flow, including fetching historical data and handling real-time updates.

Divider

The draggable element between chart panes that allows manual resizing.

Drawing Tools

Interactive tools for adding annotations to the chart:

  • Trend lines
  • Horizontal/vertical lines
  • Fibonacci retracements
  • Shapes and text

E

EMA (Exponential Moving Average)

A moving average that gives more weight to recent prices, making it more responsive to new information.

Event Hub

The centralized event messaging system that allows components to communicate via publish-subscribe pattern.

Overlay

A visual layer rendered on the chart, such as:

  • Grid lines
  • Candlesticks
  • Volume bars
  • Indicators
  • Drawing tools
  • Custom visualizations

F

Fibonacci Retracement

A drawing tool based on Fibonacci ratios used to identify potential support and resistance levels.

Frame

A single render cycle of the chart. TradeX Chart optimizes rendering to maintain smooth frame rates.

G

Graph

The component that manages the viewport and all overlays within a chart pane.

Grid

The overlay that displays horizontal and vertical reference lines on the chart.

H

High-Low

An overlay showing the highest and lowest prices within the visible range.

I

Indicator

A mathematical calculation based on price, volume, or other data used for technical analysis. Indicators extend the Overlay class and can have:

  • Their own chart pane
  • Legend with value display
  • Configuration controls
  • Custom parameters

Examples: RSI, MACD, Bollinger Bands, Moving Averages

L

Layer

A canvas rendering layer. TradeX Chart uses multiple layers for efficient rendering and hit detection.

Legend

The information panel displaying:

  • Chart title and timeframe
  • OHLCV values at cursor position
  • Indicator values and settings
  • Control buttons

Lightweight

Refers to minimal bundle size and dependencies. See comparison guide for TradeX vs Lightweight Charts.

M

MACD (Moving Average Convergence Divergence)

A trend-following momentum indicator showing the relationship between two moving averages.

Main Pane

The container holding all chart panes, timeline, and scale components.

Mjolnir.js

The single dependency used by TradeX Chart for handling touch and pointer events.

O

OHLC

Open, High, Low, Close - the four price points that define a candlestick (without volume).

OHLCV

Open, High, Low, Close, Volume - the complete data structure for a candlestick including trading volume.

Overlay

See Overlay above.

P

Pane

See Chart Pane.

Primary Pane

The main chart pane displaying price data (candlesticks). Every chart has exactly one primary pane.

R

Range

The subset of data currently visible or being processed by the chart. Includes:

  • Start and end timestamps
  • Data array
  • Index positions
  • Value max/min

Render

The process of drawing chart elements to the canvas. TradeX Chart uses optimized rendering to update only changed elements.

RSI (Relative Strength Index)

A momentum oscillator that measures the speed and magnitude of price changes, typically displayed in a secondary pane.

S

Scale

The Y-axis component showing price or value levels. Can be:

  • Linear: Equal spacing between values
  • Logarithmic: Percentage-based spacing
  • Percent: Relative to a base value

Secondary Pane

Additional chart panes below the primary pane, typically used for indicators like RSI, MACD, or volume.

SMA (Simple Moving Average)

The average price over a specified number of periods, calculated by adding prices and dividing by the count.

Snapshot

A serializable representation of the chart’s current state that can be exported and restored later.

State

The complete data structure representing the chart’s configuration, data, indicators, drawings, and theme. Can be:

  • Exported: chart.state.export()
  • Imported: Via config or chart.state.import()
  • Swapped: Multiple states can be held in memory

State Machine

A behavioral model managing chart states and transitions (e.g., idle, tool_activated, chart_pan).

Stream

Real-time data updates flowing into the chart. TradeX Chart supports streaming price data via WebSocket or other mechanisms.

T

TALib (Technical Analysis Library)

A WebAssembly-compiled library providing 100+ technical indicators. TradeX Chart integrates TALib for indicator calculations.

Theme

The visual styling configuration controlling colors, fonts, sizes, and appearance of all chart elements. Fully customizable via the config object.

Tick

A single price update in real-time data streaming.

Timeframe

The duration represented by each candlestick (e.g., 1m, 5m, 1h, 1d). Also called “interval” or “period”.

Timeline

The X-axis component showing time labels and managing time-based positioning.

Tool

An interactive feature for drawing or annotating the chart. See Drawing Tools.

V

Viewport

The visible area of the chart where overlays are rendered.

Volume

The trading volume (number of shares/contracts traded) during a time period. Often displayed as bars below the price chart.

W

Watermark

A semi-transparent image or text displayed behind chart content, typically showing the trading pair or branding.

Web Worker

A background thread for offloading heavy calculations. TradeX Chart supports Web Workers for indicator calculations.

Widget

A UI component like buttons, dialogs, or controls. TradeX Chart includes a widget system for extensibility.

Wick

The thin line extending from a candlestick body to the high or low price. Also called “shadow”.

X

X-Axis

See Timeline.

Y

Y-Axis

See Scale.

Z

Zoom

The action of changing the visible time range by increasing or decreasing the number of visible candles. Controlled by:

  • Mouse wheel
  • Pinch gestures on touch devices
  • API methods: chart.setRange()

Contributing

Found a term that should be added to this glossary? Open an issue or submit a pull request!