Portfolio Performance

Portfolio Performance is an open‑source application that tracks the complete transaction history of an investment portfolio—including purchases, sales, taxes, and fees—and computes overall performance metrics. It supports calculations of True‑Time Weighted Return and Internal Rate of Return, allowing users to assess how their holdings have performed across all accounts.

The software can import historical price data from a variety of sources such as Yahoo Finance, Quandl, AlphaVantage, CoinGecko and dedicated built‑in providers for German and US stocks. Prices are stored in XML and can be exported to CSV or JSON for further analysis. Users may also define custom asset‑allocation rules for rebalancing and maintain foreign‑currency accounts using exchange rates from the European Central Bank.

Designed for macOS, Windows, and Linux, Portfolio Performance offers a stable, mature platform for individual investors or financial analysts who need precise, multi‑account performance calculations and flexible data handling.