High-Yield Savings vs CD
You have cash to park. A CD usually pays a bit more and locks the rate — but locks your money with it. A high-yield savings account stays liquid, but the rate will move. Which one actually leaves you ahead depends on where rates go.
Your numbers
HYSA rates are variable, so the model drifts the APY each year. When the CD matures, it rolls into a new one at the then-current (drifted) rate. Negative drift = falling rates.
Strategy A: High-yield savings
Money compounds monthly at whatever the APY is right now. The rate floats — it drifts by your assumption once a year.
Balance at horizon
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Total interest earned
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Liquidity
Anytime
Strategy B: Certificate of deposit
Rate is locked for the full term, compounding monthly. At maturity, the balance rolls into a new CD at the then-current rate.
Balance at horizon
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Total interest earned
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Liquidity
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Balance over time
The real difference is the lock
The APY gap between a good HYSA and a good CD is usually small — a few tenths of a percent. What you're really choosing between is two kinds of certainty:
- A CD gives you rate certainty. Whatever happens to the Fed, your rate doesn't move until maturity. The price: your money is locked. Pulling it out early typically costs a penalty of several months' interest.
- A HYSA gives you liquidity. Withdraw any time, no penalty. The price: the rate is variable and tends to follow the Fed — when rates get cut, your APY follows within weeks.
So the question isn't really "which pays more today" — it's "do I need this money before the term is up, and which way are rates headed?"
When the CD wins
In a falling-rate environment, locking is the whole point. A 12-month CD at 4.2% keeps paying 4.2% while the HYSA drifts down to 3.9%, then 3.65%. The longer the term and the steeper the cuts, the bigger the CD's edge. CDs also win on behavior: locked money can't be impulse-spent.
When the HYSA wins
Three cases:
- Rising rates. If rates climb, your HYSA APY climbs with them while the CD is stuck at its locked rate. Set the drift positive above and watch the lines cross.
- You might need the money. An emergency fund has one job: being there. An early-withdrawal penalty on your emergency fund defeats the purpose — keep it liquid even if the CD pays more on paper.
- The gap is tiny. If the CD only pays 0.1–0.2% more, the dollar difference on a typical deposit is small enough that liquidity wins by default.
About these projections
Both accounts compound monthly. The HYSA starts at your APY and drifts by your "rate drift" amount once a year (never below 0%) — a crude stand-in for Fed moves, since nobody can actually predict them. The CD holds its rate for the full term; at maturity the balance rolls into a new CD priced at your original CD APY plus the same drift applied over the elapsed years (also floored at 0%). Real-world CD pricing at rollover will differ — banks set new-issue rates off the curve at that moment, not off a formula.
FAQ
What about CD ladders?
A ladder splits your deposit across staggered terms — say, equal slices in 6, 12, 18, and 24-month CDs. Every few months one matures, giving you a liquidity window and a chance to reinvest at current rates. It's a hedge: you get most of the CD's rate lock with some of the HYSA's flexibility. If this calculator leaves you torn, a ladder is often the honest answer.
Are HYSAs and CDs both FDIC-insured?
Yes — both are bank deposit products, insured up to $250,000 per depositor, per bank, per ownership category (NCUA provides the same coverage at credit unions). Just confirm the institution is actually a bank: some fintech "savings" products sweep into partner banks, and a few high-yield lookalikes aren't deposits at all.
What's the early-withdrawal penalty actually cost?
Typically 3 months of interest on terms under a year, and 6–12 months of interest on longer terms — charged even if you haven't earned that much yet, which can eat into principal. On a $10,000 CD at 4.2%, six months of interest is roughly $210. Breaking a CD once can erase its entire advantage over the HYSA, which is why "might I need this money?" matters more than the rate gap.