Money Markets

Certificate of Deposit

Also known as: CD, Time deposit

A deposit with a term and a rate — from the savings branch to the trillion-dollar wholesale market.

Asset class
Money markets
Instrument type
Bank time deposit (often negotiable)
Traded
Retail (non-tradable) & wholesale (negotiable)
Typical users
Savers, corporates, money funds
BeginnerWhat is it, really?

A certificate of deposit is a bank deposit with a contract: leave your money for a fixed term — three months, a year, five years — and the bank pays a fixed, usually higher, interest rate than a checking account. Withdraw early and you forfeit a penalty (typically some months of interest).

For savers, CDs are the safest yield upgrade there is: within deposit-insurance limits (e.g. $250k in the US, €100k in the EU), even the bank failing doesn't cost you principal. "CD ladders" — spreading money across staggered maturities — are the classic retail strategy for liquidity plus yield.

The same product has a giant institutional twin: negotiable CDs in $1M+ sizes, tradable in a secondary market, are a core bank funding tool bought by money funds by the hundreds of billions.

Key intuition: a CD is you doing the lending, to a bank, on bond-like terms — with the deposit insurer, not a rating agency, as your credit analyst (up to the limit).
IntermediateHow it works in practice

Retail mechanics worth knowing

  • APY vs. rate: compounding conventions differ; compare annual percentage yield.
  • Early-withdrawal penalty defines your real optionality; some "no-penalty CDs" price the option into a lower rate.
  • Callable CDs: the bank may terminate early — you've sold a rate option, compensated by extra yield (and often underpaid for it).
  • Brokered CDs: bought via brokerages, tradable but price-risky before maturity.

The wholesale market

Negotiable CDs (and their euro-market cousins) fund banks unsecured for 1–12 months. Rates track term money-market benchmarks; spread over OIS reflects bank credit — the same tension that once lived in LIBOR. Post-2023 (SVB), everyone relearned that uninsured deposits — including large CDs above the cap — are credit instruments that can run.

Bank funding context

Banks price CD specials to manage deposit betas (how fast funding costs track policy rates); rate-cycle turns show up first in CD advertising. Regulators watch brokered/wholesale CD reliance as a fragility marker.

Worked example: $100k in a 12-month CD at 4.8% APY → $4,800 interest. Early exit at month 4 with a 6-month-interest penalty (~$2,400) → net ~$800 loss versus a savings account at 4.0%: the penalty is the price of the extra 80bp, converting to a break-even holding period you should compute before buying.
AdvancedPricing & valuation

Valuing a negotiable CD

A short credit-risky zero (or coupon note for longer tenors), priced off the issuing bank's short-term curve:

$$ P = \frac{F}{1 + (r_{OIS} + s_{bank})\tau} $$

with \(s_{bank}\) the bank's unsecured term spread — observable across CD/CP/EURIBOR-panels and traded via the €STR-EURIBOR or SOFR-term bases. Secondary marks carry duration risk: a 6-month CD loses ~0.5% per 100bp — small, but "cash-like" investors have been surprised.

Retail CD as a bond with options

Fair value = riskless note + deposit-insurance wrapper − penalty-adjusted put you hold (early withdrawal) − call the bank may hold:

$$ V = B(r, T) + \underbrace{\Pi_{ins}}_{\text{insurance}} + \underbrace{P_{withdraw}(pen)}_{\text{your option}} - \underbrace{C_{call}}_{\text{their option}} $$

The withdrawal option is a fixed-strike Bermudan put on rates: valuable in hiking cycles (redeposit at higher rates); banks size penalties to blunt it. Callable CDs mirror callable-bond math — price them on a short-rate lattice or accept systematic underpayment.

System-level economics

Deposit insurance converts credit analysis into moral-hazard management: insured CDs price near-risk-free regardless of bank health (the S&L crisis's engine — insolvent thrifts bidding up insured CD rates). Caps, brokered-deposit rules and premium schedules are the containment machinery; the 2023 episodes revived every one of these debates.

Practitioner note: below the insurance cap, shop rate and penalty only — credit is the insurer's problem. Above it, you're an unsecured bank creditor; read the bank's financials or ladder under the cap across institutions.