The headline S&P 500 excludes dividends; its total-return index reinvests them. Compare the two and see how your portfolio benchmark changes the result.
SPY’s ten largest companies held 39.6% on September 11, 2026. Compare two dated snapshots and check concentration in your own portfolio.
The Treynor ratio divides return above the risk-free rate by beta. Follow a worked example and learn when low or negative beta makes it misleading.
Calculate portfolio beta as a weighted average. Follow a worked example, check the benchmark and understand missing data and other limits.
Sector labels can hide shared portfolio risks. Check company concentration, geography and factor exposure, with clear limits on what each measure shows.
The minimum variance frontier shows the lowest estimated risk for each expected return. Learn the intuition, assumptions and practical limitations.
Market, size and value factors can link stocks across sectors. Learn how factor exposure is measured and what a portfolio regression can tell you.
More holdings can still mean concentrated risk. Compare position count, effective holdings and shared exposures, then check your own portfolio.