The fixed-income market, while often talked about as a single thing, is in fact an incredibly diverse amalgamation of securities and asset types.
The U.S. bond market is currently valued at $43 trillion¹, the European sovereign debt market at nearly $11 trillion² and the global interest rate derivatives market at $436 trillion³ (at the end of 2018).
Looked at in a slightly different way, the mix of instrument types (e.g., corporate bonds, mortgages, loans), major regions (e.g., North America, Europe, Asia) and related derivative instruments (e.g., swaps, futures, ETFs) creates 72 different market classifications that all have their own market structures, participants and data needs.
1 SIFMA, 2 European Central Bank, 3 Bank for International Settlement