The Portfolio Performance tool is a free and open-source application that helps users assess the overall performance of their investment portfolios across multiple accounts. It allows individuals to meticulously track their entire transaction history, documenting various activities such as purchases, sales, fees, and taxes. The tool can retrieve historical quotes from a variety of platforms including Yahoo Finance, Finnhub.io, Quandl, and AlphaVantage, and it also has the capability to scrape data from HTML pages or JSON files. Data management is facilitated through XML storage, allowing for easy exports to formats like CSV or JSON for further analysis. Users can adjust their investment portfolios according to a custom asset allocation strategy and manage foreign currency accounts by utilizing exchange rates provided by the European Central Bank (ECB). Additionally, the application supports data imports from both CSV files and PDF documents, while generating comprehensive reports that feature detailed asset statements and performance metrics. This functionality makes it a versatile tool for anyone looking to optimize their investment strategies.