Standing rate, fees, minimum balance, and promotional expiration.
Comparing a promo rate against a standing rate, then missing the reversion.
Not finding a clever edge, per Munger's own framing.
Check the Basics Before Anything Clever
Charlie Munger's published emphasis on avoiding obvious stupidity argued that most good outcomes come from skipping basic, avoidable mistakes rather than finding a clever edge, and avoiding obvious stupidity when comparing savings accounts means running a simple checklist before opening any new account. For example, consider a saver with an $18,000 balance who compared a new account's 5.1% promotional rate against their current account's 4.0% standing rate, switched, and then saw the promotional rate revert to 3.7% after six months, a rate lower than the account they'd left, costing roughly $54 a year compared to simply staying put. The comparison itself was the mistake: promotional rates should be compared against other promotional rates, and standing rates against standing rates, never mixed. According to the USC archive of Munger's psychology speech, Munger repeatedly emphasized that avoiding a short list of common, avoidable errors does more for an outcome than seeking a sophisticated advantage. As of July 2026, this is especially important if you're comparing any promotional offer against your current account's ongoing, standing rate.
A promotional rate compared against a standing rate overstates the real gain.
Run the Checklist Every Time
Per Poor Charlie's Almanack, a short list of avoidable errors, checked consistently, was treated as more valuable than any single clever insight. Comparing standing rates against the national average of 0.38% APY and the best available 4.20% APY, using FDIC national rate data, keeps the comparison honest, and both accounts typically carry the same FDIC or NCUA coverage either way.
| Check | What it catches | Next check |
|---|---|---|
| Standing rate versus standing rate | Promotional-versus-standing mismatches | Confirm both rates are the same type |
| Monthly fees | A fee that offsets part of the rate advantage | Calculate the net rate after fees |
| Minimum balance requirement | A requirement your typical balance won't meet | Compare against your actual average balance |
| Promotional expiration date | A reversion you didn't plan for | Note the date and calendar a recheck |
Running this checklist has real benefits: it catches the specific, common mistakes that quietly erase a rate advantage. The risk of skipping it, as the reverted-promo example shows, is switching for what looks like a gain and ending up worse off within months. However, that said, it depends on which specific check applies to your situation compared to a generic worry: a fee-free account with a genuine standing-rate advantage and no minimum balance issue passes the checklist cleanly, while one with any single failed check needs a closer look. If you're deciding whether to switch to a new account, choose to switch if it passes all four checks against your current account; choose to hold off if any check reveals a mismatch. This is when this matters most: any time a rate looks meaningfully better than what you currently have.
Standing rate against standing rate, never against a promotional one.
A fee can offset part or all of a rate advantage.
A requirement you won't meet negates the advertised rate.
Calendar a recheck before any promotional rate expires.
When This May Not Apply
A promotional rate that's clearly disclosed, time-boxed, and calendared for review isn't a mistake in itself, provided you're comparing it honestly against its own reversion point, not against another account's standing rate. This is especially important to distinguish from comparing mismatched rate types by accident.
What to Do Next, in 20 Minutes
- Pull your current account's actual standing rate, not a rate you remember from opening.
- Compare it against a prospective account's standing rate, not its promotional rate.
- Check for fees and minimum balance requirements on both.
- Read avoiding obvious financial stupidity before chasing smart moves and why the boring account usually wins for related frameworks, and the quiet theft of low yields for the cost of skipping this comparison.
- Run a full Money Map check to see where your account stands today.
Sources and Methodology
This article applies Charlie Munger's published emphasis on avoiding obvious stupidity to household savings-account comparisons. It is educational and does not recommend any specific institution.
- USC Munger speech archive· Checked 2026-07-10
- Poor Charlie's Almanack· Checked 2026-07-10
- FDIC National Rates and Rate Caps· Checked 2026-07-10
- SwitchWize methodology· Checked 2026-07-10
Next scheduled verification: 2026-10-10
Educational content from the SwitchWize Research Desk. Charlie Munger and related entities are not affiliated with or endorsing SwitchWize.
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Check my savings account comparison for mistakes →Frequently asked questions
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Disclaimer
This article is educational and does not provide personalized investment, tax, legal, or financial advice. Charlie Munger, the Munger estate, Berkshire Hathaway, and related entities are not affiliated with or endorsing SwitchWize. References to public letters, speeches, and books are used for educational interpretation only.