I was surprised until I learned that mortgages are basically standardized products – the government buys almost all of them (see Bits About Money: https://www.bitsaboutmoney.com/archive/mortgages-are-a-manuf...). So what's the price difference paying for? A recent Bloomberg Odd Lots episode makes the case that it's largely advertising and marketing (https://www.bloomberg.com/news/audio/2025-11-28/odd-lots-thi...). Credit unions are non-profits without big marketing budgets, so they can pass those savings on, but a lot of people don't know about them.
I built this dashboard to make it easier to shop around. I pull public rates from 120+ credit union websites and compares against the weekly FRED national benchmark.
Features:
- Filter by loan type (30Y/15Y/etc.), eligibility (the hardest part tbh), and rate type - Payment calculator with refi mode (CUs can be a bit slower than big lenders, but that makes them great for refi) - Links to each CU's rates page and eligibility requirements - Toggle to show/hide statistical outliers
At the time of writing, the average CU rate is 5.91% vs. 6.23% national average. about $37k difference in total interest on a $500k loan. I actually used seaborn to visualize the rate spread against the four big banks: https://www.reddit.com/r/dataisbeautiful/comments/1pcj9t7/oc...
Stack: Python for the data/backend, Svelte/SvelteKit for the frontend. No signup, no ads, no referral fees.
Happy to answer questions about the methodology or add CUs people suggest.
msuniverse2026•17m ago
mhashemi•7m ago
But seriously, my favorite discovery when researching CU mortgages is the prevalence of the 15/15 ARM. It's fixed for 15 years, and then adjusts once. Most people refinance within 7 years, or move within 12. So it's like a 30Y fixed, but comes in at 20 basis points cheaper (0.2% lower APR).