Data & Analytics

Deposit beta (repricing sensitivity) — ΔAPY per 100bps, ALM/IRR model input

Deposit beta = change in deposit APY per 100bps change in a benchmark/market rate — the core credit-union/bank ALM & interest-rate-risk (IRR) model input. Derived from RateAPI's retained published deposit-rate history in extracted_rates (NOT a new scrape). Per-day segment median deposit APY is regressed (OLS) against the CD top-quartile published-rate move; the slope, expressed per 100bps, is the deposit beta. Returns per-segment beta, implied repricing lag, current APY level, peer min/median/max beta (ranked DESC), sample size (observations + credit unions), and an honest depth/confidence note. SHORT-WINDOW / retention-bounded (~5 months retained) so confidence is low; full-cycle beta needs multi-year history (roadmap). treasury/fed_funds benchmarks are not yet in-platform — v1 degrades to cd_top_quartile and discloses it (no error). Deposits quote APY, never APR. Aggregate published rates only — never member/borrower data. Single source of truth for the MCP get_deposit_beta tool and the consumer-app /deposit-beta page.

Authentication required: Pass your API key in the X-API-Key header.

post/v1/deposit-beta

Request

  • Base URL: https://api.rateapi.dev
  • URL: https://api.rateapi.dev/v1/deposit-beta
  • Auth: API key in header X-API-Key

Request body

product'savings' | 'cd' | 'share_certificate' | 'money_market' | 'ira_cd' required

Deposit product (maps to savings_type). Required.

term_monthsnumber

For CD/share_certificate/ira_cd: filter to a specific term (savings_term_months).

statestring

2-letter US state code; omit for nationwide.

window'90d' | '180d' | '365d'

History lookback window over scraped_at.

group_by'overall' | 'state' | 'cu'

Segment the beta computation: a single overall figure, per-state, or per-credit-union.

benchmark'cd_top_quartile' | 'treasury' | 'fed_funds'

Market reference. treasury/fed_funds are not yet in-platform; v1 degrades to cd_top_quartile and discloses the substitution.

Example request

{
  "state": "CA"
}

Response

Per-segment deposit beta with peer band, confidence, and depth disclosures.

productstring

Deposit product the beta was computed for.

term_monthsnumber nullable

Loan term in months.

statestring nullable

Two-letter US state code.

windowstring

How far back the history was measured.

group_bystring

What the segments were grouped by.

benchmark_requestedstring

The benchmark series the caller asked to measure against.

benchmark_usedstring

The benchmark series actually used, which can differ when the requested one has no in-platform history.

history_depth_daysinteger

Days of retained deposit history the fit was drawn from.

confidence'low' | 'moderate'

How much to trust the fit. Retained deposit history spans months rather than a full rate cycle, so this is deliberately never higher than moderate.

notestring

Plain-language explanation of what this result means.

disclosuresstring[]

Statements that must be shown to a consumer alongside this result.

Changes

No recorded changes to this operation across all 1 revision of this API.