This study identifies profitability patterns and their determinants in the global interest rate derivatives market. Although this market is the world’s largest financial market in terms of nominal value, there has been basically no academic research on profitability owing to missing data. To address this problem, a new analytical method has been developed. Using this new method, the study shows that interest rate derivatives have been a substantial source of profitability that have netted a total average annual profit of more than USD 82 billion for banks since 2009. Furthermore, the study shows that counterparty type, market position (i.e. being one of the Top 5 banks), and trade currency are determinants of the profitability of a trade. For other features of a trade, such as duration or notional amount, no correlation with profitability is found. Finally, the impact of changes of the market structure on profitability driven by regulatory initiatives is discussed qualitatively.