Joe McCann is founder, CEO and CIO of Asymmetric and an open-source software developer. His work connects trading and investment experience with tools for market-data storage, analysis and developer workflows.[1][2]
Start with Market Data Warehouse →
Links
GitHub Asymmetric 
X LinkedIn Founder, CEO and CIO · Asymmetric
Career
Before Asymmetric, McCann was a senior director in Microsoft’s Cloud and AI organization, led quantitative trading at Passport Capital and cofounded NodeSource as CEO. His company biography dates NodeSource’s exit to 2019. His current public repositories range from market research infrastructure to Markdown tools and browser automation, reflecting continued hands-on software work alongside investment management.[1][2]
Contributions
Keep a reusable local record of market history
Market Data Warehouse stores canonical market bars in Parquet files and uses DuckDB for local queries, with ClickHouse as an optional larger-scale warehouse. Its layered data flow separates raw vendor input, canonical snapshots, cleaned data and derived analytics. Atomic writes, validation and recovery address incomplete ingestion. Rebuilding query tables from the files keeps the stored data independent of one running database. It is data infrastructure, not a demonstrated profitable trading strategy.[4]
Preview Markdown while writing it
Dillinger combines a Markdown editor with a rendered preview and integrations for importing, exporting and synchronizing documents. The browser interface shortens the loop between editing plain text and inspecting its formatted result. Its repository provides a self-hostable implementation rather than only a hosted writing surface.[5]
Tools, writing & talks
Tools
Start here
Market Data Warehousegithub.comLocal-first market-history storage with Parquet, DuckDB and optional ClickHouse.
Start with the data-flow and storage sections, then inspect an ingestion command. Python, market-data conventions and vendor access help; the repository describes storage and analysis infrastructure rather than investment recommendations.
Repository owner[4]Original source