In the US treasury market, the when-issued market plays a crucial role in the bond issuance process, helping to establish pricing and expectations even before the bonds are officially issued. Here's how the when-issued market fits into the treasury auction cycle. The process begins when the treasury announces an upcoming auction. Let's say this announcement is made on March 1st with the auction set for March 5th and settlement on March 8th. The announcement includes key details such as the type of debt being issued, notes or bonds, the amount and the maturity. This information allows investors to prepare for the auction and marks the start of trading in the when issued market. Trading in the when-issued market allows investors to trade the upcoming bonds conditionally as the bonds haven't been issued yet. In our example, this would be from March 1st onwards. In this phase, bonds are typically traded based on expected yields rather than prices. As the final issuance price hasn't been set. Trading on yield helps investors align with market expectations for the auction and allows them to gauge demand based on anticipated interest rates. This yield based trading helps investors predict the auction outcome by reflecting market expectations and showing interest levels. When issued trades settle on the same day as the auctioned bonds, in our example March 8th. This ensures that trades made in the when issued market align with the official settlement date. So all trades between March 1st and March 7th will settle alongside the newly issued bonds on March 8th. When-issued trading reflects collective expectations about the auction results, offering a transparent way to assess demand and pricing dynamics. For example, strong demand in the when-issued market could drive yields down signaling high investor interest, and potentially leading to lower yields at auction. Participants in the when-issued market include primary dealers, institutional investors, and banks. These participants use this phase to manage interest rate exposure and adjust their portfolios in advance of the official issuance.