Banks profit from the gap between what they charge on mortgages and what they pay on deposits. This "net interest margin" has expanded in the post-2022 rate environment — mortgage rates rose to 6-7% while CD rates only rose to 4-5%.
Historically the gap ran about 2-3 percentage points. In 2024-2026, it has been closer to 2-2.5 for 1-year CDs vs 30-year mortgages. That narrowing reflects competitive pressure on deposits as consumers shop around.
For consumers: this data is useful for timing — if CD rates are high relative to mortgage rates, CD investments have better risk-adjusted appeal. If the gap is wide, mortgages look more attractive relative to saving.