# How do Certificates of Deposit work? **URL:** \ **Category:** Factual Questions\ **Created:** [January 6, 2026, 12:09am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387 "2026-01-06T00:09:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [January 6, 2026, 12:09am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/1 "2026-01-06T00:09:38Z")
I understand the fundamental structure of this product, but I’m confused on the details. Let’s say I put a grand in a six-month CD for 4% fixed APY. Does that mean that at the end of six months, the bank cuts me a check (or deposits to my account or whatever) for $1000 + 20 (four percent of a thousand is $40, and this is six months, so … $20?)? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 6, 2026, 12:13am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/2 "2026-01-06T00:13:05Z")
Pretty much you’ve nailed it. If you have specific questions ask away. ---
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [January 6, 2026, 12:14am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/3 "2026-01-06T00:14:19Z")
Does it matter if I put it into six-month CDs or 12-month CDs? ---
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [January 6, 2026, 12:15am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/4 "2026-01-06T00:15:31Z")
And can you roll over your dividend into the same (renewed) CD? So now you have a $1020 CD that will pay (whaterver the right sum is, I don’t have it in me to do the math) at the end of six months? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 6, 2026, 12:23am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/5 "2026-01-06T00:23:13Z")
Generally the interest rates are higher for longer instruments. So if you knew you didn’t need the money for a year, a single 1 year CD would pay better than a 6-month that you rolled into a second follow-on 6 month. Unless of course interest rates went up meanwhile, so the 2nd 6 month was available at a materially higher interest rate than the first. Of course if instead rates go down, having locked in the higher rate for longer with the 1 year is doubly good. Pays yo money & takes yo chances. And yes, auto renewed CDs are the norm; you generally have to ask special for that not to happen. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [January 6, 2026, 12:25am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/6 "2026-01-06T00:25:40Z")
You can usually have it roll over automatically at the end of the term - but at some point , the bank will contact you because if they don’t hear from you, they will have to turn the money over to the state as “unclaimed funds” . The term only matters for two reasons , the interest rate ( usually longer terms have higher rates) and whether you might need the money - there’s a penalty for early withdrawal. ---
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [January 6, 2026, 12:26am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/7 "2026-01-06T00:26:23Z")
OK, let’s say I have the money now, but want to collect it every year on November 1st, to use the dividend to put towards Christmas shopping or whatever. Should I strategically hold onto it until this November 1 and then start collecting the dividends? Or would my banker have a better idea? ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [January 6, 2026, 12:26am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/8 "2026-01-06T00:26:32Z")
A couple of nitpicks. You typically earn interest on the CD each quarter that gets reinvested back into the CD. At the end of the term (ie 6 mo, 9mo whatever), you have the option to have the bank issue you a check or roll the CD over into another term at the new interest rate. I believe the only difference with the term length is when you can remove the money without penalty and the rates the bank offers. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [January 6, 2026, 12:26am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/9 "2026-01-06T00:26:37Z")
Be aware that most banks pay interest calculated using a 360 day year. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 6, 2026, 12:29am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/10 "2026-01-06T00:29:13Z")
You didn’t ask, but … Right now money market accounts tend to pay as well as CDs with none of the fixed-term nonsense. If rates are rising unexpectedly, MMs will dynamically capture that better than CDs. OTOH if rates fall unexpected, the CDs are insulated from that decline until they renew. But the “unexpected” is key. A bank offering an e.g. 1 year CD today is not offering the current rate. They’re offering their estimate of the rate trajectory over the next 12 months. If they guess high versus subsequent reality, you win. If they guess low, you lose. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [January 6, 2026, 12:32am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/11 "2026-01-06T00:32:47Z")
> [@HeyHomie](#): > > OK, let’s say I have the money now, but want to collect it every year on November 1st, to use the dividend to put towards Christmas shopping or whatever. Should I strategically hold onto it until this November 1 and then start collecting the dividends? Or would my banker have a better idea? Interest. Not dividends. Dividends are based on profits. Interest is fees paid (in this case by the bank) for borrowing money (in this case, from you). I think you would want to time your CD so that it matures in November. Then instead of rolling the whole thing over with the dividends, just cash out and create a new CD with the principal ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [January 6, 2026, 12:39am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/12 "2026-01-06T00:39:38Z")
> [@LSLGuy](#): > > Right now money market accounts tend to pay as well as CDs with none of the fixed-term nonsense. Or even some savings accounts - I have an Openbank ( it’s a division of Santander) savings account that’s earning 4.2%. which is more than I see for CDs ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [January 6, 2026, 2:36am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/13 "2026-01-06T02:36:46Z")
> [@HeyHomie](#): > > OK, let’s say I have the money now, but want to collect it every year on November 1st, to use the dividend to put towards Christmas shopping or whatever. Should I strategically hold onto it until this November 1 and then start collecting the dividends? Or would my banker have a better idea? There’s a technique some people (like my late father) use called “laddering.” Let’s say you have $5,000 and you want to have $1,000 plus interest every year for your Christmas shopping. You put $1,000 in a one-year CD, another $1,000 in a two-year CD, another $1,000 in a three-year, etc. Each one matures on the same date, but you collect more interest (and presumably a higher interest rate) each year. The downside to this is a) the longer the term, the more a guessing game interest rates will be and b) you’ve tied up money you might need before the longer-term CDs mature. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 6, 2026, 2:42am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/14 "2026-01-06T02:42:50Z")
CDs and banks are a way for simple folks to buy big yachts for banking CEOs. They’re not a way for investors to make money for themselves with their capital, meager though it may be. IMO the OP will generally do better by forgetting that CDs exist. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [January 6, 2026, 2:49am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/15 "2026-01-06T02:49:07Z")
> [@HeyHomie](#): > > And can you roll over your dividend into the same (renewed) CD? S Often, but not always. > [@LSLGuy](#): > > They’re not a way for investors to make money for themselves with their capital, meager though it may be. They are, however- safe. Highest CD rate is hovering around 4.4%, with US savings Bonds- also safe- at about 4%. Yes, the stock market could do better- or could do worse. Historically the stock market does better, but that doesnt make the poor dudes who lost their saving in the market any happier. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 6, 2026, 2:55am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/16 "2026-01-06T02:55:29Z")
Financial experts generally recommend saving up three to six months’ worth of essential living expenses for an emergency fund. I keep this money in several short term CDs (6-month, 12-month, and 18-month) that are laddered such that one is always maturing every few months. Interest rates on these are currently around 3.5-4% (which is a bit lower than the 5% I was getting a couple of years ago), but which is also much better than the rate I am getting in a savings account or even a money market account at my credit union. They are federally insured by FDIC (for banks) or NCUA (for credit unions), so there is no risk for loss of principal. One thing that hasn’t been mentioned is that there is a penalty for early withdrawal. At my credit union, that works out to losing the last 90 days of interest for CDs with terms that are 1 year or less, or 180 days for CDs with longer terms. Note that you only pay the penalty on the amount you withdrawal, and there is never any loss of principal, only some of the earned interest. Also, when a CD matures, you can do whatever you want with the money. Pull it all out if you want, or do I what I do, which is to typically roll into another CD along with the earned interest. My credit union gives me a 21-day grace period to decide what to do after a CD matures. If I do nothing, it automatically rolls into another CD with similar terms. I always look at the current rates for the various term lengths, and decide whether to keep the one they picked, or to move the money into another CD with better terms. Finally, some CDs allow me to add more money to the account at any time, while others do not. The former ones typically offer a slightly lower interest rate (like 0.1% less). ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [January 6, 2026, 3:22am UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/17 "2026-01-06T03:22:30Z")
> [@DrDeth](#): > > Often, but not always. > > > [@LSLGuy](#): > > > > They’re not a way for investors to make money for themselves with their capital, meager though it may be. > > They are, however- safe. > Highest CD rate is hovering around 4.4%, with US savings Bonds- also safe- at about 4%. Yes, the stock market could do better- or could do worse. Historically the stock market does better, but that doesnt make the poor dudes who lost their saving in the market any happier. Yeah, I don’t look at CDs as “investments” really. I look at it as a place to park cash I may need within a year that provides a bit more return than a savings account. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [January 6, 2026, 1:04pm UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/18 "2026-01-06T13:04:14Z")
> [@doreen](#): > > Or even some savings accounts Totally agree. I think CDs are targeted at people who are scared by the idea of investing. I never saw the point in locking away your money for a long period in return for an interest rate barely, if at all, higher than a money market account. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 6, 2026, 1:25pm UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/19 "2026-01-06T13:25:44Z")
At least in the US, historically CDs preceded the invention of money market accounts. And US Savings bonds preceded CDs. CDs were a way for banks to begin to compete with the government as a place for risk-averse savers to store their principal. Note I said “store”, not invest. As @msmith537 so accurately pointed out. MM accounts & MM funds were the result of brokerages trying to get in on that same cash storage business. As to “locked away” … IIRC … In the USA originally CDs really were fixed-term. Either you couldn’t get your money out at all before they matured, or if you could you forfeited 100% of the interest earned to date. So you really had to think twice about buying a CD. And the longer the term, the greater the odds you’d need to touch the funds and get screwed. The interest rate was better, but the risk of losing all that interest was greater too. After a few years (decades?) the rules got relaxed to the current standards where there is some amount of interest forfeiture for early redemption, but it doesn’t utterly destroy the interest earned from Day 1. With the result that nowadays you shouldn’t use CDs as a place to store money you actually intend to spend during their term, but they are suited to be that 3-6 month cash cushion you expect not to touch, but could stand to do so if really needed in a personal crisis. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [January 6, 2026, 1:35pm UTC](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387/20 "2026-01-06T13:35:44Z")
That seems historically accurate. And maybe they _have_ relaxed the withdrawal rules somewhat. They’re still not something I have any interest (sic) in… [Next page](https://boards.straightdope.com/t/how-do-certificates-of-deposit-work/1026387.md?page=2)