Sofia keeps about $20,000 in a checking and savings combination at the bank she has used since college. She is not careless. She negotiates her car insurance, she uses coupons, she would never leave a tip calculator unchecked. She has simply never thought of her bank as something that is charging her, because banks do not send a bill for the interest they decline to pay. As of June 2026, her savings sits near the national average of 0.38%, which on her balance comes to about $76 a year.
(Sofia is a composite. The story is illustrative. The math is real and typical.)
What the Bank Gap Index measures
Most personal finance coverage tells you what the best account pays. That is half the picture. The number that actually describes your situation is the distance between what your bank pays and what the best account pays, because that distance is what your loyalty is costing you. We track that distance and call it the Bank Gap Index, updated against live rate data.
The construction is simple. Take the best widely available deposit rate, subtract the rate the typical bank pays, and you have the gap. As of June 2026, the top of the market sits near 4.20% and the national average sits near 0.38%, so the headline gap is about 3.6 percentage points.
SwitchWize Bank Gap Index
4.02 pp
On a $20,000 balance, that gap is worth about $804 a year. Best available: 4.40% APY. National average: 0.38% APY.
Updated from live rate data. Gap = best widely available rate − FDIC national average.
A percentage gap is abstract, so we price it in dollars on a real balance. On Sofia's $20,000, a 3.6-point gap is worth about $720 a year. That is the number her bank never prints, the interest it keeps by paying her near the floor while the top of the market pays near the ceiling.
Why the June decision widened the case, not the gap
The gap did not move much in June. What moved is the story you could tell yourself about it closing. The Fed held its benchmark at 3.50% to 3.75% and erased the single rate cut it had projected for 2026, with the median policymaker now expecting rates flat to higher and a hike openly possible.
That matters because of where the gap comes from. It is not set by the Fed. It is set by banks deciding how little they can pay and still keep your deposit. A large bank with millions of customers who never leave has no competitive pressure, so it pays near the floor. An online bank with no branches has to win every dollar, so it pays near the ceiling. The Fed's rate is the tide; the gap is the distance between two boats that choose how high to float. When the Fed was expected to cut, you could at least imagine the top boat drifting down toward yours, shrinking the gap without you lifting a finger. In June the Fed removed that current. Top rates have eased only slightly since May, and the reason to expect them to fall to the floor is gone. The gap is closer to fixed than it was before, which means Sofia's $720 a year is closer to fixed too.
Why the smartest savers miss it
The gap survives on a single misperception: that a savings account is a place to store money rather than a product that is priced. Sofia comparison-shops everything with a sticker, because the cost is visible. Her bank's cost is invisible by design. It arrives as an absence, the interest that never showed up, and people do not haggle over an absence. There is also the insurance illusion. Because her account and a top account carry the identical federal guarantee, they feel like the same product, when the only identical thing about them is the safety, not the pay. The guarantee is real. The sameness is not. One pays her $76 a year and the other pays about $800.
What to do with the gap
| When | Do this | Why |
|---|---|---|
| Measuring your bank | Judge it by the gap, not the brand | The question is how far below the top it pays, not whether it's reputable |
| Sizing the cost | Convert the gap to dollars on your own balance | A 3.6-point gap is easy to ignore; $720 a year is not |
| Deciding whether to move | Treat it as the lowest-risk decision available | Same federally insured dollar, higher rate, no market exposure added |
| Tracking the gap over time | Re-check the gap, not the Fed | It moves on bank pricing behavior, not the benchmark rate |
The Fed spent its June meeting confirming that no one is coming to close the gap for Sofia. Her bank will keep paying her $76 a year on $20,000 for as long as she reads its silence as fairness. The top of the market would pay her about $800 on the same insured balance, and the only thing standing between those two numbers is the decision to treat her bank like the priced product it has always been.
Sofia is a composite character used to illustrate typical math. Her balance and bank are hypothetical; the average and top deposit rates, the Federal Reserve decision, and the resulting dollar figures are real as of June 2026. The Bank Gap Index value shown is drawn from the SwitchWize rate archive. This article is educational and is not financial advice.
Related reading: the live Bank Gap Index and the top-paying accounts we track.
More from the idle-cash series: what the Fed's hold did to your cash, where to park idle cash now (I bonds, T-bills, high-yield savings), a CD ladder versus one long CD, and paying off the mortgage versus investing.
Sources
- Federal Reserve FOMC statements, June 2026 target hold and projections
- FDIC National Rate Survey, national average deposit rates
Use the Rate Gap calculator to turn the gap into dollars on your own balance, and see whether closing it is your biggest opportunity with a Money Map scan.
Quick answers
What is the Bank Gap Index? The distance between the national average deposit rate and the top widely available rate, currently about 3.6 percentage points, priced in dollars on a real balance.
Does the Fed control the gap? No. The Fed sets the tide; individual banks decide how little they can pay and still keep deposits. The gap is a pricing decision, not a policy outcome.
Is closing the gap risky? No. Both the account paying near the floor and the one paying near the ceiling carry the same FDIC insurance. Only the payout differs.
Why did the June Fed decision matter for the gap? The Fed erased its projected 2026 rate cut, removing the main reason to expect top rates to drift down toward the floor on their own.
Rates referenced on this page were verified on July 10, 2026 and can change after publication. This content is educational and is not personalized financial, tax, or investment advice.
Connect the lesson
Turn the article into a next step.
SwitchWize takeaway
Find your number, not the market's.
Run a Money Map to see how your cash, debt, and rates stack up against the best available options.
Start Money Map →Bank Gap Index methodology and current value: SwitchWize rate archive. Public benchmark figures cited to primary sources. Rate data reviewed June 2026.