Bond Price vs Yield Explained for the SIE Exam

Bond prices and yields move in opposite directions. When market interest rates rise, the prices of existing fixed-rate bonds fall; when market rates fall, those bond prices rise. The reason is simple: an existing bond’s coupon is fixed, so its market price has to adjust until its yield is competitive with newly issued bonds.

That matters on the SIE because debt concepts sit inside “Understanding Products and Their Risks,” the largest section of the exam at 44%. FINRA’s current exam page lists 75 scored questions, a 105-minute time limit, a passing score of 70, and a $100 fee.

Why bond prices move opposite to rates

Think of a bond as a promise with a fixed coupon. If you own a $1,000 bond with a 4% coupon, that bond pays $40 per year no matter what happens to market interest rates. If new bonds start coming out at 5%, your old 4% bond is less attractive, so its price has to drop until buyers can earn a competitive yield from it. If new bonds come out at 3%, your old 4% bond becomes more attractive, so buyers will pay more for it.

That is the “why” behind the inverse relationship. The coupon does not reset on a standard fixed-rate bond, so the market adjusts the price instead. If you hold the bond to maturity, the issuer still owes the stated interest and the face value at maturity, subject to default risk. But if you sell before maturity, the price you get is shaped by prevailing rates.

A good mental model is a seesaw: rates up, bond prices down; rates down, bond prices up. The SIE tests this as a core concept, not as a math trick. If you understand that the coupon is fixed and the price is what moves, the rest of the bond-yield topic becomes much easier.

Par, discount, and premium

Start with one simple example and keep it all the way through: a $1,000 par bond with a 4% coupon. “Par” means face value, so par is $1,000 here. A 4% coupon means the bond pays $40 per year, usually in two $20 semiannual payments.

If current market rates for similar bonds are also about 4%, the bond should trade around par, or $1,000. In that case, the bond’s stated coupon looks normal relative to the market. No price adjustment is needed.

If current market rates rise above 4%, that same bond becomes less attractive because its coupon is now below what new bonds offer. The bond will trade at a discount, meaning below par. For example, if it trades at $900, buyers are getting the same $40 annual coupon but paying less than $1,000, which pushes the yield up.

If current market rates fall below 4%, the bond becomes more attractive because its coupon is now above what new bonds offer. The bond will trade at a premium, meaning above par. For example, if it trades at $1,100, buyers still get only $40 per year, so paying more than $1,000 pushes the yield down.

One exam trap: “discount” and “premium” describe price relative to par, not quality. A bond can trade at a discount because its coupon is below current market rates. That does not automatically mean the issuer is weak or that the bond is low quality. Credit risk is a separate issue.

The four yields

The SIE usually wants you to know four yield terms in plain English.

Nominal yield is just the bond’s coupon rate, also called the stated rate. For our example bond, nominal yield is 4%, and it does not change over the life of the bond.

Current yield is the annual coupon divided by the current market price. So at par, current yield is $40 ÷ $1,000 = 4.00%. At a discount price of $900, current yield is $40 ÷ $900 = 4.44%. At a premium price of $1,100, current yield is $40 ÷ $1,100 = 3.64%. That one calculation alone helps you see why price and yield move opposite each other.

Yield to maturity (YTM) is the bond’s overall annualized return if you buy it at the current market price and hold it to maturity. In plain English, YTM looks at both the coupon payments and the fact that the bond moves toward par by maturity. If you buy at a discount, that pull up to par boosts your return; if you buy at a premium, that slide down to par reduces your return.

Yield to call (YTC) works like YTM except it assumes the bond is called on its first call date at the stated call price, instead of being held to final maturity — using the call date and call price rather than the maturity date and par at maturity.

Here is the intuition test-takers need. If our example bond is callable at par in five years, then a call speeds up the move back to par. On a discount bond, that means you get the gain from $900 back to $1,000 faster, so YTC is higher than YTM. On a premium bond, that means you lose the extra $100 above par faster, so YTC is lower than YTM. That acceleration effect is the key to keeping YTC in the right place.

The yield ladder

This is the rule to memorize, and it is the part many students flip backwards.

For a discount bond: nominal yield < current yield < YTM < YTC. For a premium bond: nominal yield > current yield > YTM > YTC. For a par bond: nominal yield = current yield = YTM; if the bond is callable at par, YTC lines up as well.

Here is the specific point people get wrong: on a premium callable bond, YTC is the lowest yield. In SIE terms, that makes it the yield-to-worst. On a discount callable bond, YTC is the highest of the four yields, because the discount is earned back sooner if the bond is called before maturity.

Bond state	Price vs. par	Coupon vs. current market rate	Yield ordering
Par	= par	Coupon = market rate	Nominal = Current = YTM
Discount	Below par	Coupon below market rate	Nominal < Current < YTM < YTC
Premium	Above par	Coupon above market rate	Nominal > Current > YTM > YTC

This table is the SIE-safe summary to remember. The par row comes from the fact that a bond bought at par has no premium to lose and no discount to gain back, while the discount and premium rows reflect how current yield, YTM, and YTC change as price moves below or above par.

Interest-rate risk basics

Not all bonds move by the same amount when rates change. Two basic rules matter most on the SIE: longer maturity means more interest-rate risk, and lower coupon means more interest-rate risk. Shorter maturity and higher coupon mean less sensitivity to rate changes.

Why? Because with a long-term bond, more of the bond’s value depends on cash flows that arrive further in the future, so a change in rates has more time to affect today’s price. And with a low-coupon bond, more of the value is tied up in the principal payment at the end, which also makes the price more sensitive. In duration language, longer maturity and lower coupon generally mean higher duration.

A quick quote-convention note, since it sometimes shows up around debt questions: corporate bonds are quoted as a percentage of par and are commonly taught for SIE purposes in eighths, while U.S. Treasury notes and bonds are quoted in 32nds. So a corporate quote of 98 means about $980 per $1,000 bond, while Treasury pricing uses fractional 32nds of price per $100 of par.

For the equity side of the capital-structure story — common stock, preferred stock, and where each sits in liquidation relative to bondholders — see our common vs preferred stock explainer.

Exam traps to avoid

Do not reverse the ladder. On a discount bond, yields rise as you move from nominal to current to YTM to YTC. On a premium bond, they fall in that same order. If you remember only one bond-yield pattern for the SIE, remember that one.

Do not assume YTC is always the worst yield. Yield to worst is the lower of YTM and YTC. On a premium callable bond, YTC is typically the lower one. On a discount callable bond, YTC is the higher one, because the discount is recovered faster.

At par, keep it simple. Nominal yield, current yield, and YTM are equal at par. Students often overthink par questions because they expect a trick. Usually there is no trick.

Do not confuse “discount” with “junk.” A bond can trade below par simply because its coupon is lower than current market rates. Credit quality is a different concept and is tested separately from the price-yield relationship.

Once the yield ladder feels automatic, test yourself with the free SIE diagnostic to see how the SIE actually frames discount/premium and YTM/YTC questions.

Frequently asked questions

Why do bond prices fall when interest rates rise?

Because the coupon on an existing fixed-rate bond stays the same while new bonds may offer higher rates. If new issues pay more, the existing bond has to sell at a lower price so that buyers can earn a competitive yield from it.

What’s the difference between current yield and yield to maturity?

Current yield looks only at this year’s coupon income relative to the bond’s current market price. YTM goes further and estimates the bond’s overall annualized return if you buy it at the current price and hold it until maturity, including the effect of any discount or premium moving back toward par.

Which yield is highest on a discount bond?

On the standard SIE yield ladder for a callable discount bond, YTC is the highest. The reason is that if the bond is called, the investor gets back par sooner, which accelerates the gain from buying below par.

What does it mean when a bond trades at a premium?

It means the bond is trading above par, usually because its coupon is higher than current market rates for similar bonds. Buyers are willing to pay more for that above-market coupon, but paying more pushes the bond’s yield down.

Is a long-term or short-term bond more affected by rate changes?

A long-term bond is generally more affected by rate changes than a short-term bond of similar credit quality. The same basic idea applies to coupon size too: lower-coupon bonds are generally more rate-sensitive than higher-coupon bonds.

If a bond trades at par, which yields are equal?

At par, nominal yield, current yield, and YTM are equal. If the bond is callable at par, YTC will line up as well, which is why par questions are usually the simplest yield questions on the exam.

If you want one clean takeaway to carry into the exam room, make it this: fixed coupon, moving price. Once you understand that the coupon stays put and the market price is what adjusts, par, discount, premium, current yield, YTM, and YTC all start to fit together instead of feeling like separate facts to memorize.