The 20-Year Bond Is Changing The Shape of The Yield Curve

At a Glance

  • Front-end rates are indicating lower and stable interest rates, while longer dated rates have moved higher
  • 20-year bonds were issued in May for the first time since 1986, the last time the yield curve held its current shape

The U.S. Treasury issued $20 billion in new 20-year bonds on May 20, the first such issuance since 1986. This new 20-year bond slotted into a part of the yield curve where only decade-old 30-year bonds trade. On June 17,the Treasury issued another $17 billion of the same $20-year CUSIP.  Since the 20-year re-emerged, interesting trends have formed that are helpful to follow.

Kink in The Curve

Below is an update on the cash traded yield curve via the Treasury Analytics tool from QuikStrike. Overall, the curve has been steepening during the month of June.  Front-end rates are indicating lower and stable interest rates, while longer dated rates have moved higher. Notice how the 20-year sector has maintained a kink throughout this time.

Source: QuikStrike, Treasury Direct

The kink in the curve at the 20-year point is explained partially by the additional supply from the May 20 auction, and partially by the fact that prior to the auction, the curve was simply a straight line between the 10-year and the 30-year. Looking at yield curves prior to 1986, when the 20-year was last a benchmark, that kink was normal. It was driven by both lack of liquidity and lack of demand in the sector.

The shape of this part of the curve is frequently viewed through a curve butterfly or “fly,” a formula that subtracts two times the 20-year bond yield and adds the 10-year note and 30-year bond yields. It is a visual measure of the shape of the curve. Using end-of-month par treasury yield curve data from the U.S Depart.ment of the Treasury from 1976 to present, one can see the behavior of this part the curve for around the last 45 years.

Source: US Treasury Department

Narrowing the focus down to the mid-1980s, the last time the 20-year was issued, the curve shape was quite positive and grew more so when Treasury discontinued the issuance of the 20-year year bond. The 10/20/30 implied Treasury butterfly went highly negative as the economy and stocks struggled into ‘Black Monday’ on October 19, 1987.

Source: US Treasury Department

As liquidity builds in the sector, experts anticipate the kink will moderate as it was back in the 1980s, for the reasons Owain Johnson outlined in his article from May 7, including more longer-dated issuance, relative value trading, spread trading, and managing the risk of longer-dated exposures.

Futures Trading

With the new 20-year belonging to the Classic Bond’s deliverable basket, the long-end of the futures curve has seen increased activity. The proportion of U.S. Treasury futures open interest held in Classic Bond and Ultra Bond futures has grown to multi-year highs. The Bond-Ultra BOB yield curve spread on CME Globex, which offers an efficient proxy for the May 2040-Nov 2045 cash spread, has been highly active with YTD spread volume up 151% vs. 2019.

The newly issued 1.125 of May 15, 2040 is currently the most expensive to deliver and trade on spread to the 4.5s of February 15, 2036, the current CTD of the Classic Bond futures. While not a candidate to switch anytime soon, the Treasury Analytics tool is quite helpful to understand the nuances of the baskets, quickly see the underlying securities, and access top level analytics such as maturity, DV01, conversion factors and futures yield.

The 20-Year Impact

On June 17, the US Treasury issued another $17 billion of 20-year bonds. Increases in trading in the long-end can help reinforce liquidity for both futures and cash. As the 20-year bond issuance outstanding grows, it is likely that more issuance will beget more trading that will beget more liquidity.


Eric Leininger is Executive Director of Financial Research and Product Development at CME Group.

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