What problem does it solve? Trading and fintech applications fail in predictable ways: JavaScript float arithmetic silently corrupts PnL calculations, WebSocket connections drop without reconnecting, charts leak memory on symbol changes, and strategy parameters get changed randomly without tracking what was tested. This Skill enforces safe patterns across the entire trading stack so these failures are caught before they reach production. ## Core Features & Use Cases - Safe Money Handling: Enforces Decimal.js/BigInt arithmetic at parse boundaries with banker's rounding, audit trails, and Grep-based audits that flag raw float operations on price, amount, or balance fields. - Real-Time Data & Charts: Provides WebSocket lifecycle management with exponential backoff reconnect, event normalization, TanStack Query cache invalidation, and TradingView Lightweight Charts candlestick rendering with reduced-motion support. - Streaming Indicators & Strategy Experiments: Computes SMA, EMA, RSI, MACD, Bollinger Bands, and VWAP incrementally per tick, and runs a scientific experiment loop (hypothesize, backtest, analyze, record) with quant metrics like Sharpe ratio, max drawdown, Kelly criterion, and Monte Carlo simulation. - Use Case: When building a crypto trading dashboard, the Skill detects decimal.js or ws in package.json, then guides implementation of a reconnecting WebSocket feed, a candlestick chart with indicator overlays, and a backtested entry/exit strategy with results recorded to .rune/experiments/. ## Quick Start Ask the AI to build a real-time candlestick chart with a reconnecting WebSocket feed and Decimal-safe price handling for your trading dashboard.
