CD ladders

A CD ladder is an arrangement, not a product. The depositor takes a sum that would otherwise sit in a single liquid account, divides it into equal portions, and places each portion in a CD of a different maturity — say, $5,000 each in a 1-year, 2-year, 3-year, 4-year, and 5-year CD. After the first year, the 1-year CD matures and is reinvested into a new 5-year CD; the original 2-year CD has become a 1-year CD in remaining term; and so on. After the ladder has cycled through one full maturity rotation, a CD matures every year, the funds are always within one year of accessibility, and the depositor earns the prevailing 5-year rate on each maturing rung (since each is reinvested at five years).

This article describes the mechanics of a ladder, the conditions under which it produces a meaningful rate advantage, the alternatives it competes with, and the situations in which it is the wrong tool. For the underlying CD product, see certificates of deposit; for the principal alternative for liquid balances, see high-yield savings accounts.

The construction

A standard ladder is built around equal-sized rungs at evenly spaced maturities. For a five-rung, five-year ladder built at time zero:

• Year 0: open a 1-year, 2-year, 3-year, 4-year, and 5-year CD, each with the same principal.
• Year 1: the 1-year CD matures; reinvest the proceeds into a new 5-year CD.
• Year 2: the original 2-year CD matures; reinvest into a new 5-year CD.
• Year 3: the original 3-year CD matures; reinvest.
• Year 4: the original 4-year CD matures; reinvest.
• Year 5: the original 5-year CD matures; reinvest. The ladder is now fully composed of 5-year CDs in various stages of seasoning, with one maturing each year.

The principal variant is the shorter ladder — quarterly or monthly maturities over a shorter horizon — which is suitable when the depositor wants more frequent access. A monthly ladder of 12 1-year CDs, opened one each month for a year and rolled at each maturity, gives access every month and earns the 1-year rate; a quarterly ladder of 20 5-year CDs, similarly rolled, gives access every quarter and earns the 5-year rate. The frequency of the rungs determines the frequency of access; the term of each rung determines the rate earned.

What the ladder optimises for

The ladder addresses two specific concerns that a single CD does not.

The first is access risk. A single 5-year CD pays the 5-year rate but cannot be accessed for five years without paying an early-withdrawal penalty. A ladder of equal-rung 5-year CDs, after the first year, pays close to the 5-year rate on the whole pool and gives access to roughly one-fifth of the balance each year without penalty. The ladder thus partially decouples the rate-from-term and the access-from-term decisions.

The second is reinvestment risk. If a depositor places the entire sum in a single 5-year CD and rates rise during the term, the depositor is locked into the lower rate; if rates fall during the term, the depositor enjoys the higher locked rate but reinvests at the lower rate at maturity. A ladder spreads the reinvestment exposure: in any given year, only one-fifth of the principal is being reinvested at the prevailing rate, smoothing the yield path against rate-cycle volatility.

The ladder does not protect against the average level of rates — if rates fall and stay low, the ladder eventually rolls down with them. It protects against the specific reinvestment-timing risk of concentrating maturity in a single date.

When the ladder is the wrong tool

The ladder is most useful in two specific conditions: when CDs offer materially higher rates than alternative liquid deposits, and when the depositor wants the structure of a rolling-maturity schedule. Neither condition is universal.

If the rate curve is flat or inverted (CDs of different maturities paying similar or lower rates than each other), the ladder offers little or no rate advantage over simpler structures. If high-yield savings accounts pay rates comparable to or higher than 1-year CDs — a common configuration in periods of rapidly rising short-term rates — the entire ladder underperforms a single high-yield savings account that pays the prevailing rate continuously, with full liquidity and no rolling administration.

If the depositor's actual liquidity need is "all of it, sometime in the next year, on a date I cannot predict," a no-penalty CD or a high-yield savings account is structurally better suited than a ladder. The ladder works best when the depositor has a balance that is genuinely investible for several years but wants the staggered access as a hedge against unanticipated needs.

If the depositor is using brokered CDs in a brokerage account, the laddering exercise is much simpler operationally — the brokerage platform typically supports automated ladder construction — but the underlying considerations are the same. The brokered-CD secondary market gives some additional flexibility (rungs can be sold rather than broken with penalty), at the cost of price risk in the secondary market.

Comparison with money market and high-yield savings

The principal alternatives to a CD ladder for the same money are a money market deposit account, a high-yield savings account, or (outside the deposit world) a Treasury-bill ladder in a brokerage account. The trade-offs:

• High-yield savings account. Full liquidity at all times, no rolling administration. Pays whatever the institution's posted rate is, which can change at any time. Better than the ladder when the high-yield savings rate is close to or above the CD rate; worse when the CD rate is materially higher and stable.
• Money market deposit account at a branch bank. Full liquidity, tiered rate, often lower yield than either a CD or a high-yield savings account. Comparable to the ladder in convenience but typically inferior in rate.
• Treasury-bill ladder. Constructed in a brokerage account, holding 4-week, 8-week, 13-week, 26-week, and 52-week Treasury bills, rolled at maturity. State-tax-exempt income, backed by the full faith and credit of the U.S. government rather than by FDIC insurance. Operationally more complex than a CD ladder, with no FDIC overlay but no FDIC limit either; suitable for balances above $250,000 where the FDIC limit would otherwise constrain a CD strategy at a single bank.

Limits and uncertainty

CD ladders are a long-standing depositor strategy; the mechanics have not changed in any meaningful way. The rate environment in which ladders are most attractive — meaningfully upward-sloping deposit curve — has been variable over the past five years, and the rise of competitive high-yield savings products has narrowed the conditions under which a ladder dominates. A depositor considering a ladder should compare the prevailing rates and consider whether the structural features (rolling access, reinvestment smoothing) are worth the operational overhead in the current environment. The basic technique is durable; its competitive position is rate-dependent.