Yes — the most efficient quartile grew 6.85% year-over-year, the least efficient grew 4.15%. A 2.7pp gap, or roughly 1.7× the growth rate.
All 1,809 federally insured US credit unions with $100M+ in assets, split into efficiency-ratio quartiles. Outcome: year-over-year asset growth at the latest quarter.
| Efficiency quartile | Avg (efficiency quartile) | Range | Credit unions | Avg asset growth YoY | Median asset growth YoY |
|---|---|---|---|---|---|
| Q1 — most efficient | 42.3% | 8.8% – 50.0% | 453 | 6.85% | 6.63% |
| Q2 | 54.1% | 50.1% – 57.7% | 452 | 6.92% | 5.55% |
| Q3 | 61.4% | 57.8% – 65.2% | 452 | 5.23% | 4.73% |
| Q4 — least efficient | 71.9% | 65.3% – 122.6% | 452 | 4.15% | 3.11% |
Lower efficiency ratio = fewer cents spent to generate each dollar of revenue. CUs in the top efficiency quartile (averaging 42.3%) grew assets at 6.85% YoY. CUs in the bottom quartile (averaging 71.9%) grew at 4.15%.
The conventional narrative — "you have to spend to grow" — isn't visible in the data. If anything, the relationship runs the other way: operational discipline frees capital that funds growth, and inefficient CUs are stretched thin enough that they can't reinvest in member-facing capacity.
A 2-3pp gap in annual asset growth compounds quickly. Over five years, the top-quartile CU is roughly 15-20% larger than its bottom-quartile peer started equal. The efficiency ratio is one of the cheapest single metrics to track and one of the highest-signal.
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.