Convexity in Bonds: Definition, Meaning, and Examples

Because every bond has a unique structure and issuer, it is impossible to dole out advice on the exact relationships. But because call and put options generally affect maturity you can make informed guesses as to the affect on convexity. If the duration is high, the bond’s price will move in the opposite direction to a greater degree than the change in interest rates. Using the concept of duration, we can calculate that Bond A has a duration of 4 years while Bond B has a duration of 5.5 years. This means that for every 1% change in interest rates, Bond A’s price will change by 4% while Bond B’s price will change by 5.5%. Wealth managers can provide valuable insights and advice on constructing and managing a diversified bond portfolio that considers convexity considerations.

Managing the interest rate risk exposure of MBS relative to Treasury securities requires dynamic hedging to maintain a desired exposure of the position to movements in yields, as the duration of the MBS changes with changes in the yield curve. The amount and required convexity risk frequency of hedging depends on the degree of convexity of the MBS, the volatility of rates, and investors’ objectives and risk tolerances. First and second derivatives are important in finance – in particular in measuring risk for fixed income and options.

  1. Wealth managers can provide valuable insights and advice on constructing and managing a diversified bond portfolio that considers convexity considerations.
  2. Because of this assumption of whether cash flows will change or not, the results from the calculations of modified convexity and effective convexity can be very different.
  3. While current implied volatility indicates a tight probability distribution of forward rates, the inflationary factors summarized in Exhibit 1 point to potential tail risk.
  4. As a general rule of thumb, if rates rise by 1%, bond prices fall by 1% for each year of maturity.

If market rates rise, new bond issues must also have higher rates to satisfy investor demand for lending money. The price of bonds returning less than that rate will fall as there would be very little demand for them as bondholders will look to sell their existing bonds and opt for bonds with higher yields. Eventually, the price of these bonds with the lower coupon rates will drop to a level where the rate of return is equal to the prevailing market interest rates.

Is there any other context you can provide?

The biggest change is the increase in Federal Reserve holdings, partly offset by a large reduction in the actively hedged GSE portfolio. Finance Strategists is a leading financial education organization that connects people with financial professionals, priding itself on providing accurate and reliable financial information to millions of readers each year. At Finance Strategists, we partner with financial experts to ensure the accuracy of our financial content. As such, they should not be construed as investment advice, nor do the opinions expressed necessarily reflect the views of CFA Institute or the author’s employer.

Why is convexity important for bond investors?

Related to the bond market, the speed of your car is called duration, while the speeding up/slowing down is known as convexity. The higher the convexity, the more dramatic the change in price given a move in interest rates. After a while, if your bond is experiencing negative convexity, it also slows down/loses value. As the US Federal Reserve lays the verbal groundwork for an eventual real-world quantitative easing (QE) taper, bond prices are dropping at an accelerated rate. In order to understand the ramifications of a Federal Reserve taper on the prices of a bond or bond portfolio, what is needed is a bond convexity primer.

In this article, we have shared our insights into convexity risk regardless of the direction of potential rate changes. The key takeaway is that life insurers are not compensated for taking convexity risk and it is the right time for insurers to review convexity exposure. There are different approaches available to mitigate convexity exposure through rebalancing of asset positions and hedges within each life insurer’s risk limits.

Duration hedging of MBS can be done with interest rate swaps or Treasury bonds and notes. When rates decline, hedgers will seek to increase the duration of their positions. This can be achieved by buying Treasury notes or bonds, or by receiving fixed payments in an interest rate swap.

Unlike conventional mortgages, ARMs don’t decline in value when market rates increase, because the rates they pay are tied to the current interest rate. The low-rate environment in early 2013 had arguably set the stage for a convexity event (historically low https://1investing.in/ rates coupled with substantial negative convexity). As the ten-year yield rose from 1.70 percent in early May to 2.90 percent in August, mortgage portfolio durations extended significantly, forcing MBS hedgers to sell duration, or to sell the underlying MBS.

Convexity and Risk

For example, with a callable bond, as interest rates fall, the incentive for the issuer to call the bond at par increases; therefore, its price will not rise as quickly as the price of a non-callable bond. The price of a callable bond might actually drop as the likelihood that the bond will be called increases. This is why the shape of a callable bond’s curve of price with respect to yield is concave or negatively convex. When Yields increase from Y0 to Y2 the price of the bond with the more convex price yield relationship (red curve) decreases by a smaller amount (from P0 to P1) than the price of a bond with the less convex price yield relationship (blue) (P0 to P2). When yields decrease from Y0 to Y1, the price of the bond with the more convex yield curve shows a much higher increase (from P0 to P4) as opposed to the price of the bond with a less convex price-yield relation (from P0 to P3). By selecting bonds with different convexity characteristics, investors can create a bond portfolio with a more balanced exposure to interest rate fluctuations, reducing the potential impact of rate changes on their investments.

Because of this assumption of whether cash flows will change or not, the results from the calculations of modified convexity and effective convexity can be very different. In the case of option free bonds where the cash flows would not vary if interest rates were to vary, the convexity measure, regardless of whether modified or effective, would always be positive. Coupon-paying bonds typically have lower convexity than zero-coupon bonds, as their periodic coupon payments reduce their overall price sensitivity to interest rate changes. Bonds with positive convexity experience price increases that are larger than the price decreases when interest rates change by equal amounts. A bond’s price is determined by the present value of its future cash flows, which include periodic coupon payments and the principal repayment at maturity. By incorporating convexity into their analysis, investors can better estimate the potential impact of interest rate changes on their bond portfolios and make more informed investment decisions.

Bond duration measures the change in a bond’s price when interest rates fluctuate. If the duration of a bond is high, it means the bond’s price will move to a greater degree in the opposite direction of interest rates. If rates rise by 1%, a bond or bond fund with a 5-year average duration would likely lose approximately 5% of its value.

Voss holds a BA in economics and an MBA in finance and accounting from the University of Colorado. The LSE editors ask authors submitting a post to the blog to confirm that they have no conflicts of interest as defined by the American Economic Association in its Disclosure Policy. Note, however, that we do indicate in all cases if a data vendor or other party has a right to review a post.

Negative Convexity: Definition, Example, Simplified Formula

As indicated, the larger the change in interest rates, the larger the error in estimating the price change of the bond. Bank liabilities, which are primarily the deposits owed to customers, are generally short-term in nature, with low duration statistics. By contrast, a bank’s assets mainly comprise outstanding commercial and consumer loans or mortgages. These assets tend to be of longer duration, and their values are more sensitive to interest rate fluctuations. In periods when interest rates spike unexpectedly, banks may suffer drastic decreases in net worth, if their assets drop further in value than their liabilities.

How confident are you in your long term financial plan?

The higher a bond’s duration, the larger the change in its price when interest rates change and the greater its interest rate risk. If an investor believes that interest rates are going to rise, they should consider bonds with a lower duration. In the example figure shown below, Bond A has a higher convexity than Bond B, which indicates that all else being equal, Bond A will always have a higher price than Bond B as interest rates rise or fall. In order to immunize a portfolio against interest rates changes, a portfolio manager would like the assets and liabilities to respond in an identical manner when interest rates change. This is why a portfolio manager will try to match the duration of assets to the duration of liabilities in order to make the assets as sensitive to interest rate changes as the liabilities response to these changes. Therefore including the convexity measure adjusts the duration only approximated price change in such a way as to result in a better estimation of actual price change.

As a general rule of thumb, if rates rise by 1%, bond prices fall by 1% for each year of maturity. Low-coupon and zero-coupon bonds, which tend to have lower yields, show the highest interest rate volatility. In technical terms, this means that the modified duration of the bond requires a larger adjustment to keep pace with the higher change in price after interest rate moves.

While the statistic calculates a linear relationship between price and yield changes in bonds, in reality, the relationship between the changes in price and yield is convex. Banks employ gap management to equate the durations of assets and liabilities, effectively immunizing their overall position from interest rate movements. Therefore, if their durations are also equal, any change in interest rates will affect the value of assets and liabilities to the same degree, and interest rate changes would consequently have little or no final effect on net worth. Therefore, net worth immunization requires a portfolio duration, or gap, of zero. These options can cause bond prices to be more sensitive to interest rate changes in one direction than the other, leading to asymmetric price responses to rate fluctuations.

If a bond’s duration rises and yields fall, the bond is said to have positive convexity. As yields fall, bond prices rise by a greater rate or duration than if yields rise. If a bond has positive convexity, it would typically experience price increases as yields fall, compared to price decreases when yields increase. A bond’s convexity is the rate of change of its duration, and it is measured as the second derivative of the bond’s price with respect to its yield.