Note and Bond Futures: Conversion Factors, CTD, and the Quality Option

Treasury note and bond futures are among the most heavily traded financial contracts in the world. Unlike a SOFR futures contract, which references a single rate, a T-note futures contract allows the short party to deliver any eligible Treasury bond from a defined basket. This delivery option — the quality option — creates the central pricing challenge of bond futures: the futures price is set by reference to the cheapest-to-deliver (CTD) bond, which is the bond the short would choose to deliver under current market conditions. As yields change, the CTD bond can switch from one issue to another, creating non-linear dependence on yield levels and a gap between the futures price and a naive no-arbitrage calculation. The quality option, plus the timing option (the short chooses which day in the delivery month to deliver), makes bond futures pricing genuinely complex.