The U.S. Treasury market routinely sees around $1 trillion in trading on an average day. That scale is a useful reminder that bonds are not a niche part of finance. Governments issue them to borrow, while companies can use them to raise capital without issuing additional ownership shares.
But a bond does not simply appear in an investor’s account. It begins with an issuer that needs financing, reaches investors through the primary market, and—if it is marketable—can later change hands in the secondary market.
The Primary Market: Where Bonds Are Born
A newly issued bond enters the primary market. This is the stage where an issuer raises financing by selling new securities to investors.
For U.S. Treasury securities, issuance takes place through auctions. Treasury announces the securities it plans to issue, investors submit bids, and the auction determines which bids are accepted. Primary dealers are important participants and are expected by the Federal Reserve Bank of New York to bid in every Treasury auction, but they are not the only participants; other institutions and individual investors can participate as well.
Corporate bonds follow a different route. A company issuing debt typically works with one or more investment banks as underwriters. The banks help structure and price the offering and distribute the newly issued bonds to investors. Once the issue is completed, the company receives the proceeds from the financing and investors hold the new bonds.
The scale can become enormous when companies have a strong reason to borrow. In 2020, investment-grade companies issued a record $1.9 trillion of corporate bonds, as historically low interest rates encouraged companies to borrow and refinance existing debt.
The Secondary Market: Where Existing Bonds Trade
Once a bond has been issued, it can change hands in the secondary market. Here, investors buy and sell existing bonds rather than provide new financing to the original issuer.
Unlike stocks, which commonly trade through exchange-based order books, many bonds trade over the counter (OTC) through direct dealer relationships or electronic platforms.
This structure historically made bond trading less transparent than exchange-traded markets, particularly for corporate bonds. A major change came with the introduction of FINRA’s Trade Reporting and Compliance Engine (TRACE) in 2002. TRACE provides post-trade information about many completed bond transactions, giving investors much greater visibility into recent market activity than they once had.
Who Participates in the Bond Market
Large institutions play an especially important role in bond markets, but the participants vary across different types of bonds.
Dealers help connect buyers and sellers and are central to many over-the-counter bond markets. Asset managers, pension funds, and insurance companies are major investors, holding bonds for purposes ranging from portfolio management to meeting long-term obligations.
Banks, central banks, and foreign official institutions also participate in different parts of the market. In government-bond markets especially, some of these institutions can hold or trade very large amounts of securities.
Individual investors participate as well, either by buying bonds directly or through investment funds.