AptiStockX is a native, local-first desktop stock charting and portfolio research application for Windows, macOS, and Linux. It is the modern continuation of AptiStock, first released in 2005, and is designed for self-directed traders and researchers who want control of their chart files, market data, watchlists, and workspaces. AptiStockX supports transparent local CSV data, configurable market-data providers, technical indicators, custom indicators, drawing studies, watchlists, reusable workspaces, multiple chart windows, and multi-monitor workflows. Version 3.1 adds a searchable global stock symbol catalog, a dockable Global Market Stock Viewer, market and instrument filters, offline symbol search, and integrated chart and download workflows for supported global markets. It also expands line-study tools and improves catalog updating and chart rendering.