Bank discount yield, holding period yield, effective annual yield, and money market yield

CFA level I / Quantitative Methods: Basic Concepts / Discounted Cash Flow Applications / Bank discount yield, holding period yield, effective annual yield, and money market yield

The bank discount yield is calculated as the annualized discount as a percentage of the par value of a bond based on the 360-day period. The Treasury bills are quoted using the bank discount yield.

Bank discount yield (BDY), rBD = (D/F)(360/t)

where
rBD = the annualized yield on a bank discount basis
D = the dollar discount = face value of the Treasury bill - market value of bond at the time of purchasing
F = the face value of the Treasury bill
t = the actual number of days remaining to maturity

Example 6: Calculating bank discount yield

What is the bank discount yield for a Treasury bill trading at $98,000? The face value of the Treasury bill is $100,000, and it has 180 days left until maturity.

Solution:

Discount to the face value (D) = 100,000 - 98,000 = 2,000
Bank discount yield = (2,000/100,000)(360/180) = 4.00 percent.



Example 7: Calculating T-bill price given its bank discount yield

A Treasury bill is quoted at a bank discount yield of 3.00 percent. The bill has 120 days to maturity. Compute the market price of the Treasury bill.

Solution:

Bank discount yield = 3.00 percent
Unannualized discount for 120 days period = 0.03(120/360) = 0.01
Dollar discount on the face value = 0.01*100,000 = 1,000
Market price of the Treasury bill = Face value of bill - Dollar discount on the bill = 100,000 - 1,000 = $99,000.


The holding period yield it the return realized on investment over the holding period of the investment. It is an unannualized return measure.

HPY = (P1 - P0 + D1)/P0

Where
P0 = initial investment
P1 = price at the end of the holding period
D1 = cash paid by the investment at the end of the holding period

For an interest bearing bond, if the bond is sold between the coupon dates then any interest accrued should be added to the trade price to calculate the holding period yield.

For a pure discount security, the holding period yield is simply the difference between the selling price and purchase price divided by the purchase price. HPY = D/P0 where D = P1 - P0.

Example 8: Calculating the holding period yield for a pure discount bond

A zero-coupon bond was bought at a price of $850 and is sold at a price of $984. What is the holding period yield for the bond?

Solution:

Holding period yield for a pure discount bond = (P1 - P0)/P0 = (984-850)/850 = 15.76 percent.

The effective annual yield is equal to the annualized holding period yield.

EAY = (1+HPY)(365/t) - 1 We can also convert EAY to HPY.

HPY = (1+EAY)(t/365) - 1

Example 9: Calculating the effective annual yield

Mohan bought a stock for $45 and sold it after 180 days for $47.5. The stock also paid a dividend of $0.5 at the end of 180 days. What is the effective annual yield realized by Mohan from investing in the stock?

Solution:

For calculating the effective annual yield, we need to calculate the holding period yield first.

HPY = (P1 - P0 + D1)/P0 = (47.5 - 45 + 0.5)/45 = 6.67 percent
EAY = (1+HPY)(365/180) - 1 = 1.0667(365/180) - 1 = 13.98 percent.

The money market yield is the annualized holding period yield based on a 360-day year. It is also referred to as CD equivalent yield. The money market yield is computed on the purchase price whereas the bank discount yield is calculated on the face value.
MM = HPY*(360/t)
rMM = (360*rBD)/[360 - (t)(rBD)]

It is advisable to calculate the HPY from the bank discount yield and then calculate the money market yield. That is an easy way to do it rather than remembering the formula to convert bank discount yield to money market yield.

Derivation of the second formula of money market yield from the first one

HPY = Dollar Discount/(Face Value – Dollar Discount) = D.D./(F.V. – D.D.)

(D.D./F.V.)*(360/t) = rBD

D.D. = (t/360)*(F.V.)*rBD

HPY = (t/360)*(F.V.)*rBD/[F.V. – (t/360)*(F.V.)*rBD] = t*rBD/(360 – t*rBD)

rMM = HPY*(360/t) = [t*rBD/(360 – t*rBD)]*(360/t) = 360*rBD/(360 – t*rBD)



Example 10: Calculating money market yield

A Treasury bill is trading at $98,500, and it has 270 days to maturity. The face value of the bill is $100,000. What is the money market yield for the bill?

Solution:

Holding period yield (HPY) = (100,000-98,500)/98,500 = 1.52 percent
Money market yield = HPY(360/t) = 0.0152*(360/270) = 2.03 percent.



Example 11: Converting bank discount yield to money market yield

The bank discount yield of a Treasury bill is 2.50 percent. The bill has 180 days to maturity. What is its money market yield?

Solution:

This question can be solved in two ways. The first way is to simply remember the formula of converting bank discount yield to money market yield and apply the formula.

Money market yield, rMM = (360*rBD)/[360 - (t)(rBD)] = (360*0.025)/[360 - 180*0.025] = 2.53 percent.

The other way is a little longer one, but it is advisable to solve the question using this way as you don't want to risk forgetting the formula.

Bank discount yield = 2.50 percent
Suppose the face value of the bill = 100,000
Total dollar discount = 100,000*0.025*(180/360) = 1,250.
Market price of the bond = 100,000 - 1,250 = 98,750.
Holding period yield = 1,250/98,750 = 1.266 percent
Money market yield = HPY(360/t) = 0.01266*(360/180) = 2.53 percent.


The bond equivalent yield is the semiannual discount rate multiplied by two. The bonds in the USA are quoted in the bond equivalent yield. Most of the bonds in the USA pay semi-annual coupons. So, a semi-annual yield is calculated, and that is simply multiplied by two to get the bond equivalent yield.

Bond equivalent yield = = 2*Semiannual yield = 2*[(1+HPRt)(6/t) - 1]

where
HPRt = holding period yield for a holding period of t months

Example 12: Calculating bond equivalent yield

The holding period yield for a bond is 0.8 percent. The bond was held for one month only. What is the bond equivalent yield for the bond?

Solution:

We first need to calculate the semi-annual yield.

Semiannual yield = (1+Monthly holding period yield)6 - 1 = 1.0086 - 1 = 4.897 percent.

Bond equivalent yield = 2*Semiannual yield = 2*4.897 percent = 9.79 percent.


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