| Domain Model | The core domain objects representing the trading system state (e.g., Instrument, Order, Position). |
| MessageBus | The central messaging backbone for inter-component communication, supporting event-driven Pub/Sub and Req/Res patterns. |
| Instrument | A tradable asset or contract (e.g., Equity, Futures, CryptoPerpetual). |
| Venue | The execution venue or exchange where trading occurs (e.g., BINANCE, IB, OKX). |
| Quote Tick | Top-of-book market data (Level 1) representing the current best bid and ask prices. |
| Trade Tick | A discrete record of an executed trade in the market. |
| Bar | An aggregation of market data (OHLCV) over a specified interval (time, tick, or volume). |
| Order Book | A consolidated record of outstanding limit orders organized by price levels (Level 2 depth). |
| ExecutionEngine | The component responsible for order lifecycle management, routing, and fill processing. |
| DataEngine | The component managing market data ingestion, subscription routing, and Bar aggregation. |
| RiskEngine | The pre-trade risk management component enforcing constraints (e.g., order rate limits, maximum notional, and position sizing). |
| Portfolio | The manager of account balances, aggregate positions, and mark-to-market valuation. |
| Cache | A low-latency, in-memory data store maintaining the current state of the trading system. |
| Adapter | A connectivity layer component that interfaces with external venue APIs or market data feeds. |
| Backtest | The process of simulating algorithmic trading strategies using historical market data. |
| Sandbox | A paper trading environment utilizing live market data with simulated matching and execution. |
| Live | The production environment where algorithms route live orders to execution venues with real capital. |
| Slippage | The discrepancy between the expected execution price and the actual fill price. |
| Latency | The time interval between a market event and the system’s reaction (e.g., tick-to-trade latency). |
| Sharpe Ratio | A metric measuring risk-adjusted return (excess return per unit of volatility). |
| Max Drawdown | The maximum observed peak-to-trough decline in the portfolio’s net asset value. |
