Perpetual Bond

Quick Definition

A perpetual bond (also called a "perp" or "consol") is a bond with no maturity date that pays a fixed coupon to holders indefinitely — theoretically forever. The issuer is never obligated to repay the principal; investors receive only ongoing interest payments. Perpetual bonds are used by governments (historically) and banks (as regulatory capital) to raise long-term funding.

What It Means

Most bonds have a specific maturity date — 5 years, 10 years, 30 years — when the principal is repaid. A perpetual bond never matures. You lend $1,000, receive coupons forever, but the $1,000 principal is never returned (unless the bond has a call option).

This sounds unusual, but it has practical logic:

For issuers: No bullet repayment obligation ever. The liability never comes due. For investors: A guaranteed income stream — valuable for insurance companies and pension funds that need to match long-duration liabilities.

Historical Background: Consols

The most famous perpetual bonds were British consols (consolidated annuities), issued by the British government beginning in 1751. The UK government issued consols to fund wars — including the Napoleonic Wars, the Crimean War, and even World War I. The coupons were paid continuously until 2015, when the UK government finally redeemed the last outstanding consols.

The very last consol redemption in 2015 paid off bonds originally issued 265 years earlier — an extraordinary example of the perpetual bond's longevity.

How Perpetual Bonds Are Valued

Since there is no principal repayment, a perpetual bond's value is the present value of its infinite coupon stream:

Price = Annual Coupon / Required Yield

Example:

• Annual coupon: $50 per $1,000 face value (5% coupon)
• Current market required yield: 5%
• Price = $50 / 0.05 = $1,000 (at par)

Now suppose interest rates rise and investors require 6.25% yield:

• New Price = $50 / 0.0625 = $800

The price has fallen 20% because rates rose. This illustrates perpetual bonds' extreme interest rate sensitivity — they have the highest duration of any fixed-income instrument.

Duration of a Perpetual Bond

Duration measures interest rate sensitivity. For a perpetual bond:

Duration = (1 + Yield) / Yield

At 5% yield: Duration = 1.05 / 0.05 = 21 years

This means a 1% rise in interest rates would cause roughly a 21% fall in price — far more volatile than a 10-year Treasury note (duration ~8-9 years).

Modern Perpetual Bonds: AT1/CoCo Bonds

The most actively traded perpetual bonds today are Additional Tier 1 (AT1) capital instruments, also called Contingent Convertible bonds (CoCos), issued by banks to meet regulatory capital requirements under Basel III.

What AT1 Bonds Are

After the 2008 financial crisis, regulators required banks to hold more equity capital. AT1 bonds are a hybrid instrument that:

• Count as regulatory capital (equity-like for capital purposes)
• Pay a fixed coupon (bond-like for investor income)
• Can be permanently written down or converted to equity if the bank's capital falls below a trigger level
• Are perpetual (no maturity) but callable at the bank's option after 5 years

The Credit Suisse AT1 Controversy (2023)

In March 2023, UBS acquired Credit Suisse in a government-arranged emergency merger. Swiss regulators wrote down Credit Suisse's $17 billion of AT1 bonds to zero — while equity shareholders received a small payout. This was unusual because AT1 bonds are senior to equity in the capital structure; conventional insolvency theory would pay bondholders before equity holders.

The Swiss regulatory decision shocked the AT1 market globally, triggered a temporary selloff across all bank AT1 bonds, and raised serious questions about the legal certainty of these instruments. The episode illustrated the unique risks of AT1 perpetual bonds.

AT1 vs. Regular Bonds

Yield Comparison: Why Investors Buy Perps

Perpetual bonds typically offer significantly higher yields than senior bonds from the same issuer, compensating investors for:

• No maturity (interest rate risk never resolves)
• Subordination in capital structure
• Coupon cancellation risk (issuers can skip coupons without triggering default)
• Write-down/conversion risk (AT1 bonds specifically)

Illustrative yield comparison for a major European bank:

The AT1 pays nearly double the senior bond yield — reflecting the substantial additional risk.

Corporate Perpetual Bonds

Some corporations issue perpetual bonds (without the AT1 regulatory features) for flexible, long-term capital:

Why companies issue corporate perps:

• Rating agencies may treat some perps as equity-like, improving credit ratios
• Long-duration liability matches long-duration assets (utilities, infrastructure)
• No refinancing risk — no maturity cliff to refinance

Notable corporate perpetual bond issuers include utility companies (AES, Southern Company), Asian conglomerates, and some REITs.

Call Features on Perpetual Bonds

Most modern perpetual bonds are callable — the issuer can redeem them at a specified date (typically 5-10 years from issuance) at par:

• First call date: Earliest the issuer can redeem at par
• Coupon step-up: If not called on the first call date, coupon increases sharply (incentivizing the issuer to call)
• Market convention: Issuers are expected to call at first opportunity; failure to call signals financial distress

When Credit Suisse failed to call an AT1 bond in 2023, it sent a signal of distress to markets even before the emergency merger was arranged.

Key Points to Remember

• A perpetual bond pays interest forever with no maturity date — the principal is never repaid (unless called)
• Price = Coupon / Required Yield — perpetual bonds are the most interest-rate-sensitive fixed-income instruments
• AT1 (Additional Tier 1) bonds are the dominant modern perpetual bonds — used by banks as regulatory capital and carrying unique risks including coupon cancellation and write-down
• The Credit Suisse AT1 wipeout (2023) demonstrated that AT1 bonds can be written to zero even when equity receives some value — a critical risk to understand
• Most perps are callable after 5 years — market convention expects issuers to call at the first opportunity; failure to call signals distress

Frequently Asked Questions

Q: Would I ever buy a perpetual bond as an individual investor? A: Generally no for most individual investors. AT1 bonds are complex instruments with capital structure subordination risk and write-down features that require sophisticated analysis. Some AT1 bonds trade in denominations as low as $1,000, but understanding the risks requires institutional-level credit analysis.

Q: If a perpetual bond has no maturity, how can I ever get my money back? A: Either wait for the issuer to exercise the call option (most perps are called within 5-10 years), or sell in the secondary market. Most AT1 bonds trade in liquid markets among institutional investors.

Q: What happens to perpetual bond investors if the issuer goes bankrupt? A: For AT1 bonds, write-down may occur before bankruptcy as a going-concern loss absorption. For ordinary corporate perps, holders are unsecured creditors and receive a recovery based on their position in the capital structure — typically very low given their subordination. Recovery rates on perpetual bonds in bankruptcy are generally poor.

Q: Why do some Asian companies issue so many perpetual bonds? A: Asian accounting standards and rating agency treatment can allow perpetuals to be classified as equity on the balance sheet, reducing reported debt and improving leverage ratios. This makes the instrument attractive for capital structure management, explaining the high volume of corporate perpeptual bonds from Asian issuers.