American Express vs Zynlo Bank
High-Yield Savings Accounts Comparison
Last Updated: September 5, 2025
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Summary of American Express vs. Zynlo Bank
As of September 5, 2025 American Express offers an APY of 3.50% for its High Yield Savings Account, with a minimum balance of $0, compared to Zynlo Bank's 4.35% APY for its Tomorrow Savings Account, with a minimum balance of $0.01.
Zynlo Bank yields $85 more than American Express on a $10,000 balance after one year. American Express pays $350, while Zynlo Bank pays $435 - an APY advantage for Zynlo Bank.
American Express
Strengths
- American Express has a high App Store rating of 4.9.
- No maintenance fees for the High Yield Savings Account.
Potential Drawbacks
- American Express has a BBB rating of F and is not accredited.
- No branches available for in-person banking.
Zynlo Bank
Strengths
- Zynlo Bank offers a higher APY of 4.35% for the Tomorrow Savings Account.
- Zynlo Bank has a BBB rating of A+.
Potential Drawbacks
- Zynlo Bank has a lower App Store rating of 4.0.
- No branches available for in-person banking.
Summary: American Express offers a competitive APY of 3.50% but has a poor BBB rating of F. In contrast, Zynlo Bank provides a higher APY of 4.35% and boasts a strong BBB rating of A+, making it more appealing for savers. However, both banks lack physical branches and have lower App Store ratings, with American Express at 4.9 and Zynlo at 4.0.
Compare American Express' vs Zynlo Bank's Savings Accounts
| American Express | Zynlo Bank | ||
|---|---|---|---|
| Product | High Yield Savings Account | vs | Tomorrow Savings Account |
| APY | 3.50% (as of 9/5/2025) | 4.35% (as of 9/5/2025) | |
| Bundled Account | No | No | |
| FDIC-insured | Yes | Yes | |
| Online Only | Yes | Yes | |
| Compound Frequency | Daily | Daily | |
| Minimum Deposit | $0 | $10 | |
| Minimum Balance for APY | $0 | $0.01 | |
| Maintenance Fee | $0 | $0 | |
| Direct Deposit Required | No | No | |
| App Store Rating | 4.9/5 | 4.0/5 | |
| Google Play Rating | 3.8/5 | 3.5/5 | |
| BBB Rating | F | A+ |
Comparative Historical APY Insights (Last 6 Months)
| American Express | Zynlo Bank | ||
|---|---|---|---|
| Product | High Yield Savings Account | vs | Tomorrow Savings Account |
| Latest APY | 3.50 % | 4.35 % | |
| Trend | Sideways | Sideways | |
| Slope (bps/mo) | -4.2 | 0.0 | |
| Rate Changes / Mo | 0.35 | 0.00 | |
| Days Since Last Change | 44 | 172 | |
| High (-6 m) | 3.70 % | 4.35 % | |
| Low (-6 m) | 3.50 % | 4.35 % | |
| Draw-down from High | -5.4 % | 0.0 % | |
| Volatility (CV) | 0.021 | 0.000 |
APY Insights Glossary
- Latest APY
- Most recent advertised annual-percentage yield.
- Trend
- Direction over the last 6 months (regression slope).
- Slope (bps/mo)
- Average monthly change; 10 bps = 0.10 pp.
- Rate Changes / Mo
- Typical number of APY moves per month.
- Days Since Last Change
- Recency of the latest APY adjustment.
- High (-6 m)
- Highest APY in the last 173 days.
- Low (-6 m)
- Lowest APY in the last 173 days.
- Draw-down from High
- How far today sits below the 6-month peak.
- Volatility (CV)
- Coefficient of variation = stdev ÷ mean.
Why Track Savings-Account APYs?
- See how quickly a bank reacts to Fed moves or competition.
- Gauge “twitchiness” - frequent moves can annoy savers.
- Spot if you're buying near a peak (draw-down) or riding a rise.
- Slope (bps/mo) shows speed of change.
- Volatility (CV) scales jumps by average level.
Calculate Savings Growth for American Express vs Zynlo Bank
All calculations are based on APY.
American Express
APY: 3.50%
Total savings breakdown:
- Interest earned: $2,114.1 (10.51%)
- Total contributions: $13,000 (64.63%)
- Initial deposit: $5,000 (24.86%)
Your total balance
$20,114.10
Effective APY: 3.50% (based on your deposit and contributions)
Total balance: $20,114.1
Earnings: $2,114.1
Bank OverviewZynlo Bank
APY: 4.35%
Total savings breakdown:
- Interest earned: $2,662 (12.88%)
- Total contributions: $13,000 (62.92%)
- Initial deposit: $5,000 (24.20%)
Your total balance
$20,662.00
Effective APY: 4.35% (based on your deposit and contributions)
Total balance: $20,662
Earnings: $2,662
Bank OverviewWith a $5,000 initial deposit and $13,000 in total contributions over 5 years, American Express's total earnings would be $547.9 lower than Zynlo Bank's total earnings.
The Banksparency Savings Calculator provides estimated savings growth based on user input and our latest data.
More Comparisons
Compare American Express' APY of 3.50% with other banks
Compare Zynlo Bank's APY of 4.35% with other banks
| Bank Pair | Competitor APY | Min Deposit |
|---|---|---|
| Zynlo Bank vs Ally Bank | 3.50% | $0 |
| Zynlo Bank vs Axos Bank | 4.46% | $0 |
| Zynlo Bank vs Bank of America | 0.01% | $100 |
| Zynlo Bank vs Barclays | 4.10% | $0 |
| Zynlo Bank vs BrioDirect | 4.30% | $5,000 |
| Zynlo Bank vs Capital One | 3.50% | $0 |
| Zynlo Bank vs Chase Bank | 0.01% | $0 |
| Zynlo Bank vs Chime | 3.75% | $0 |
| Zynlo Bank vs CIT Bank | 4.00% | $100 |
| Zynlo Bank vs Discover Bank | 3.50% | $0 |
| Zynlo Bank vs Elevault | 4.60% | $0 |
| Zynlo Bank vs EverBank | 4.30% | $0 |
| Zynlo Bank vs Fitness Bank | 4.75% | $100 |
| Zynlo Bank vs FVCbank | 4.35% | $500 |
| Zynlo Bank vs GO2bank | 4.50% | $0 |
| Zynlo Bank vs Marcus by Goldman Sachs | 3.65% | $0 |
| Zynlo Bank vs Neighbors Bank | 4.60% | $0 |
| Zynlo Bank vs Newtek Bank | 4.35% | $0 |
| Zynlo Bank vs Peak Bank | 4.35% | $100 |
| Zynlo Bank vs Pibank | 4.60% | $0 |
| Zynlo Bank vs Presidential Bank | 4.50% | $5,000 |
| Zynlo Bank vs Santander Bank | 0.03% | $25 |
| Zynlo Bank vs SoFi Bank | 3.80% | $0 |
| Zynlo Bank vs Synchrony Bank | 3.80% | $0 |
| Zynlo Bank vs TIMBR | 4.40% | $1,000 |
| Zynlo Bank vs UFB Direct | 4.21% | $5000 |
| Zynlo Bank vs Varo Bank | 5.00% | $0 |
| Zynlo Bank vs Wells Fargo | 2.51% | $25 |