# Buffer ETF methodology

> How ETFIQ computes every figure for 431 buffer ETFs as of Oct 21, 2026: scope, sources, nightly checks and what it cannot tell you.

Data as of Oct 21, 2026. Rebuilt every trading night.

This specification describes the data as published on Oct 21, 2026 , covering 431 funds. Rebuilt every trading night.

## Buffer ETF methodology

What is covered, where each figure comes from, how it is worked out, and what it cannot tell you. Check any of it yourself.

431 Funds covered

Oct 21, 2026 Figures as of

Nightly Rebuilt from the raw sources

### Scope

431 defined outcome ETFs from 8 issuers: AllianzIM, Calamos, Corgi, First Trust, Innovator, PGIM, TrueShares, iShares. A fund is covered when its issuer publishes daily outcome-period values for it on a public page. Funds without daily values are left out. ETFIQ does not estimate between filings.

413 of 431 funds carry an SEC series ID and CIK, matched by ticker, then by name, against the SEC series and class file. Tickers are reused after a fund closes, so a ticker alone is not enough.

### Sources

| Source | What it provides | Read | Spec |
| --- | --- | --- | --- |
| Issuer outcome-period pages | Starting cap, remaining cap, buffer, downside before buffer, period start and end, fund and reference return | Every trading night | · |
| Prospectus supplements (SEC 485BPOS) | Buffer geometry and participation terms at period start | On filing | document |
| SEC series and class file | Series id and CIK for each fund | Weekly | document |
| Prospectus XBRL | Expense ratio | Weekly | document |

### Definitions and method

Each figure is labeled as the issuer’s or ETFIQ’s.

Can still gain (issuer) The most the fund can still return from today to the end of its outcome period, after fees. This is the issuer’s remaining cap, in fund-price terms. Fall before buffer (issuer) How far the fund can fall from today before its buffer starts to absorb losses. This is the issuer’s downside before buffer, in fund-price terms. Protection left (ETFIQ) How much of the buffer is unused, in index points. If the buffer runs from b start to b end in reference-return space and the reference has returned R since the period started, the buffer used so far is max(0, min( B , b start − R )) where B = b start − b end . Protection left is B minus that. It is in index points, not fund-price points, because the buffer is set on the index. The outcome band (ETFIQ) One axis per fund, from the buffer floor to the cap in reference-return space, with two markers: where the reference index sits and where the fund sits. The same axis for every fund lets you compare funds with different buffers and start dates. Outcome period The window over which the issuer’s cap and buffer apply, from period start to period end. Figures mean nothing outside it, so the period dates appear beside every fund.

### What is checked every night

Independent code recomputes each published figure from the issuer pages. It re-derives protection left from the buffer geometry and the reference return, and re-derives the band position. It confirms each fund’s issuer comes from a curated rule or a confirmed SEC registrant, never the fund name.

### What this cannot tell you

- A daily snapshot, not a forecast. Figures show where a fund stands today, not where it will finish.

- The stated buffer applies only over a full outcome period. Buy mid-period and you get what is left of it. Protection left measures that.

- Buffer funds hold FLEX options, not shares. There is no holdings look-through and no overlap figure between two of them.

- Figures are as of the issuer’s own publication, for most issuers the prior close.

### How to check any of this

Every published figure is free as JSON on the open data page . Use ETFIQ's figures with attribution and the as-of date. Issuer data stays under its owner's terms. Independent code recomputes every number nightly from the raw sources, and the statistics page shows the result. Errors are listed on the corrections page .

A figure marked ETFIQ is one ETFIQ computed. Every other figure is the issuer’s or the exchange’s, and is labeled that way.

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Source: ETFIQ, independent ETF data. Recomputed nightly from public filings and prices.
Cite: ETFIQ, Buffer ETF methodology, data as of Oct 21, 2026. https://etfiq.com/methodology/buffer
Licence: https://etfiq.com/license/ Figures ETFIQ computes are free to use with attribution: ETFIQ (etfiq.com). Issuer data stays under its owner's terms.
HTML: https://etfiq.com/methodology/buffer