Does Interactive Brokers Pay Interest on Cash? How to Work Out the Rate You Will Actually Get
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By Spencer Li, CFTe · Last updated: 17 October 2026
Yes. Interactive Brokers (IBKR) pays interest on the settled cash in your account, automatically, with nothing to sign up for and nothing to move into a separate product. The interest accrues every day and lands once a month, on the third business day of the following month.
The rate itself moves, because IBKR sets it as a benchmark rate minus a fixed spread, so it rises and falls with the market. Then three rules decide how much of it reaches you. The first slice of cash in each currency earns nothing, the full rate goes only to accounts worth 100,000 US dollars or more, and smaller accounts earn a share in proportion to their size. So the rate in IBKR’s advert is the most you can earn, and most people reading this page will earn less.
Why did one trader earn less than IBKR advertised?
On 14 November 2023, a trader on Reddit’s r/singaporefi described moving cash into IBKR after running IBKR’s own interest calculator. They waited two weeks, worked out the rate from the interest actually paid, and wrote: “I found the interest rate to be much less as advertised.”
It is a fair complaint, and a useful one, because almost everyone who opens an account does the same sum. They take the interest paid, divide it by all the cash they put in, and compare the answer with the headline. IBKR never promised the headline on all of that cash, and the reason sits in the fine print of its own interest page, which says the overall interest you get “will be a blended rate”.
Blended means your cash is cut into slices, and each slice earns its own rate.
For US dollars, the first 10,000 earns nothing at all. The rate on the rest is then scaled by the size of your whole account, which IBKR measures as net asset value, or NAV, meaning your cash plus everything you hold, valued at today’s prices. IBKR’s calculation notes put it plainly: an account with a NAV of 50,000 “earns credit interest at a rate equal to one-half the rate” paid to accounts worth 100,000 or more.
Suppose your account is worth 80,000 US dollars, and 20,000 of it is sitting in cash. The first 10,000 earns nothing. The other 10,000 earns 80% of the posted rate, because 80,000 is 80% of 100,000. Spread across all 20,000 of your cash, that works out to:
(0 + 0.8 × 10,000) ÷ 20,000 = 40% of the posted rate
So a trader in that position, checking the interest paid against the advert, would see well under half the headline and assume something had gone wrong. Nothing had. IBKR’s own comparison table runs this exact account and lands on the same 40%.
The same arithmetic is kinder to bigger accounts and harsher to small ones. An account worth 320,000 with 80,000 in cash earns the full rate on 70,000 of it, which blends to 87.5% of the posted rate. An account worth 20,000 with 5,000 in cash earns nothing at all, because every dollar of that cash sits inside the free slice.
So the trader on Reddit was right in the way that matters. As at 17 October 2026, IBKR’s Singapore interest page still opened with an “Earn up to” figure, and the blended rate a smaller account actually earns sits further down, inside the calculator. If your account is worth less than 100,000 US dollars, the advert is describing someone else’s account.
If you trade around a full-time job and would rather spend your 15 minutes a day on charts than on interest tiers, my free 15-minute swing trader checklist is the daily routine I use myself.
Where does the rate come from?
IBKR does not pick a number out of the air each month. Every currency has what IBKR calls a reference benchmark, which it builds from “internationally recognized reference rates (such as Fed Funds)”, bank deposit rates, and rates from the currency and money markets. The rate you earn is that benchmark minus a spread. For US dollars, IBKR Pro clients get the benchmark minus 0.5%, and IBKR Lite clients get the benchmark minus 1.5%.
The spread is set by IBKR and rarely changes, while the benchmark moves with the central bank. When the Federal Reserve cuts rates, the US dollar benchmark falls, and your interest follows it down without anyone sending you an email about it. So any blog post that quotes a single rate, including an older version of this one, starts going stale the day it is published.
The snapshot below was taken once, on one day. Please check IBKR’s live interest page before you rely on any of it.
| Currency | Slice that earns 0% | IBKR Pro rate above it, as at 17 Oct 2026 | How IBKR labels it | Benchmark this implies |
|---|---|---|---|---|
| US dollar | first 10,000 | 3.380% | benchmark minus 0.5% | 3.88% |
| Singapore dollar | first 14,000 | 0.514% | benchmark minus 1% | 1.514% |
| Japanese yen | first 5,000,000 | 0.826% | benchmark minus 0.25% | 1.076% |
| Swiss franc | first 100,000 | minus 0.446% | benchmark minus 0.25% | minus 0.196% |
On the same day, IBKR Lite paid 2.380% on US dollars above the first 10,000, which is the full one point lower that the spread predicts.
The table shows something the advert does not. Idle Singapore dollars were a much weaker case than idle US dollars, with a lower benchmark, a wider spread and a bigger free slice all working against you at once. So, as at 17 October 2026, IBKR was a poor place to park spare Singapore dollars, and I would rather say so than pretend otherwise.
What does “long settled cash” actually mean?
IBKR’s pages talk about interest on “long settled” cash, and the phrase sounds like money that has been sitting quietly in a corner for a long time. It means something much simpler. In trading shorthand, a long balance is a positive one, the opposite of a short balance, which is money you owe. IBKR’s own wording elsewhere is “positive settled cash balances”.
So there is no waiting period beyond settlement. Proceeds from a sale start earning once the trade has settled, and IBKR even says that cash funded before an account is approved may start earning before the account is open.
A few quieter rules can each shave your interest without any warning on screen.
- The free slice applies per currency. Hold 10,000 US dollars and 14,000 Singapore dollars, and both piles sit entirely inside their free slices, so the account earns nothing, even though NAV is counted across all your currencies together.
- Separate accounts are never added together. Two IBKR accounts each worth 60,000 are treated as two accounts worth 60,000, never as one worth 120,000.
- Cash in the commodities segment earns nothing. IBKR pays only on the securities side of the account, and offers a sweep to move spare cash across.
- Accrued interest cannot be withdrawn until it is posted. It sits in your statement all month and only becomes real cash on that third business day.
There is also an odd quirk in how the daily interest is counted. IBKR’s calculation notes divide the US dollar rate by 360 days, an old money-market habit, and then pay it on all 365 days of the calendar year. So you collect about 1.4% more interest than the headline suggests, and that is 1.4% of the rate itself, nowhere near 1.4 extra points. It is a small consolation for the free slice.
Which currency is your cash really sitting in?
Most people assume interest on cash can only ever be good news. IBKR’s page says otherwise. For balances in Swiss francs, Japanese yen or Russian roubles, it says IBKR “may apply an effective negative rate”. A negative rate means you pay IBKR for the privilege of holding the money. Size does not help. IBKR adds that the negative rate is the same whatever the size of the account, so the small-account discount offers no protection here.
The snapshot above shows how quickly that list changes. On 17 October 2026 the Swiss franc carried a negative rate for Pro clients, while the yen paid 0.826% above its free slice. Russian roubles now convert automatically into US dollars or euros, and for any other currency where the effective rate drops below zero, IBKR pays 0% rather than charging you. Israeli shekels and Indian rupees earned nothing at any size.
So the currency matters as much as the amount, and you can end up holding one you never meant to choose, simply because you sold a Japanese stock last month and the yen proceeds stayed exactly where they landed. Or imagine you buy a US stock with Singapore dollars and never convert them. IBKR quietly lends you the US dollars, so the account now holds negative US dollars and positive Singapore dollars. You pay interest on the loan at the benchmark plus a spread, and you earn the benchmark minus a spread on the Singapore dollars, if they clear the free slice at all. Most people only notice this when the monthly statement arrives, usually with some regret and a small amount of swearing.
Checking which currencies your cash sits in takes a minute, and it belongs in a daily routine, which is what my free 15-minute swing trader checklist is for.
Should you leave the cash at IBKR, or put it to work?
There is one more layer that comes up whenever people read IBKR’s interest page closely, which is the auto-swap program. It uses currency swaps to net large long and short cash balances against each other, and IBKR describes it as a sophisticated strategy, “only available to qualifying investors with cash balances of at least 10M USD”. Outside the US, IBKR also asks for a professional investor classification in the UK, the EU and most of Asia-Pacific. If you are reading this to understand the interest on a few thousand dollars, it does not apply to you, and that is fine.
The more practical choice is between floating and fixed. Cash interest floats with the benchmark and asks nothing of you. A short US Treasury bill locks in a yield until it matures, at the cost of an order, a commission and a decision. I worked through that comparison, with the fees and the withholding tax question, in how to buy US T-bills on Interactive Brokers, so I will not repeat it here.
Personally, I think the first question is never which instrument pays more. It is how much of your cash a trade might need next week. Cash that has to be ready for a setup belongs in cash, and the free slice and the proportional rate only decide what the waiting costs you.
FAQ
Does Interactive Brokers pay interest on uninvested cash?
Yes. IBKR pays interest on positive settled cash automatically. The rate is a benchmark minus a spread, the first slice of each currency earns nothing, and accounts worth less than 100,000 US dollars earn a proportional share.
How much do I need at IBKR to earn the full rate?
Your account needs a NAV of 100,000 US dollars or more, counting stocks and cash together. Even then, the first 10,000 US dollars of cash earns nothing, and the full rate applies to the cash above it.
Why is my IBKR interest lower than the advertised rate?
Because the advert shows the highest rate. Your actual rate blends a zero on the free slice with a rate scaled to your account size, so an account worth 80,000 with 20,000 in cash earns about 40% of the posted rate.
When does IBKR pay interest on cash?
Interest accrues daily and is posted monthly, on the third business day of the following month. Until it is posted, accrued interest cannot be withdrawn.
Does IBKR pay interest on Singapore dollars?
Yes, above the first 14,000 Singapore dollars, at the Singapore dollar benchmark minus a spread. The SGD benchmark and spread are both less generous than the US dollar’s, so check the live rate before parking SGD there.
Can IBKR cash interest be negative?
Yes. IBKR says balances in Swiss francs, Japanese yen or Russian roubles may carry a negative rate, the same for every account size. Other currencies whose rate falls below zero earn 0%.
Did the free slice or the 100,000 rule change the sum for you, and which currency has your idle cash ended up in? Let me know in the comments.
If you have not opened the account yet, start with Interactive Brokers for beginners, then how to open and set up an account and how to deposit and withdraw funds. How much of your money should be in the market at all is covered in my guide to money and risk management, and the rest is in my free trading guides.
And if you want a routine that keeps your trading to 15 minutes a day, grab the free 15-minute swing trader checklist.
About the author. Spencer Li is The 15-Minute Trader and the founder of Synapse Trading. He is a Certified Financial Technician (CFTe) with 15+ years of trading, run from 70+ countries. He holds a B.Acc and B.BM from SMU. Every trade he takes is public, dated, losses left in. He teaches rules-based swing trading in 15 minutes a day, one system for any market.
Education, not financial advice. Synapse Trading is not licensed by MAS to advise on investment products. Trading carries risk of loss, and past performance is not indicative of future results.
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Educational content only, not personalised financial advice. Trading carries risk, including loss of capital. Past performance is not indicative of future results. Synapse Trading is not licensed or regulated by MAS.
