No — the data inverts the conventional wisdom. The fastest-growing loan books (Q4, averaging 15.9% YoY) have the lowest delinquency at 0.77%. The shrinking books (Q1, averaging -4.7%) have the highest at 1.11% — 1.4× as much, a 0.33pp gap.
All 1,809 federally insured US credit unions with $100M+ in assets, split into loan-growth quartiles. Outcome: current delinquency rate at the latest quarter.
| Loan growth quartile | Avg (loan growth quartile) | Range | Credit unions | Avg delinquency rate | Median delinquency rate |
|---|---|---|---|---|---|
| Q1 — shrinking | -4.7% | -18.6% – -0.5% | 453 | 1.11% | 0.87% |
| Q2 — slow growth | 1.6% | -0.5% – 3.7% | 452 | 0.85% | 0.71% |
| Q3 — moderate growth | 5.9% | 3.7% – 8.4% | 452 | 0.81% | 0.71% |
| Q4 — fastest growth | 15.9% | 8.4% – 130.0% | 452 | 0.77% | 0.67% |
The intuition behind the hypothesis — "fast loan growth eats credit standards" — isn't visible in the 2025 NCUA data. The relationship runs the other direction: CUs that grew loans aggressively have cleaner books than CUs whose books are shrinking. The shrinking quartile isn't shrinking on purpose; it's shrinking because the existing book is going bad.
A caveat: brand-new loans haven't seasoned. Some of the cleanness in the top growth quartile is just that aggressive 2025 originations haven't had time to default yet. The next 12-18 months will tell us whether that's optical or structural. We'll re-run this every quarter as new NCUA data lands — track this URL for the seasoned-book version.
For a CU board: this is the conversation that should follow the conservative-lending posture. "Holding back to protect credit quality" doesn't show up in the industry data — if anything, holding back correlates with the credit problems it was meant to prevent. The underlying mechanism is probably that the fastest growers are also the strongest underwriters, not that loan growth itself is causal.
Tudovu Research is published from NCUA call-report data via CU Growth Plan. New analysis each quarter as fresh data lands.
Tudovu's Industry Data Explorer runs this same analysis on a custom peer set — pick the asset tier, state, charter type, or specific competitors and we'll show you where your CU sits in the curve.