Index Fund
A mutual fund or ETF designed to track the performance of a specific financial market benchmark (e.g., S&P 500, Total World Stock Index) with low expense ratios; reduces company-specific risk by tracking a broad index; market risk remains.
Systems Engineering Analogy
A read-only mirror of the broader economic state: reduces company-specific risk by tracking a broad index; market risk remains.
Featured in: Book 02: Buy the Average