Get started

Methodology

How we source our data

Every figure on Underly comes from a primary source — the issuer that runs the fund, the exchange it lists on, or the ATO. This is the full list, how current each one is, and what happens to it before it reaches a page.

ByMAppFin, GAICD· Founder · Updated

The sources

We read these directly. Each links to the publisher's own page so you can check any figure against the original.

Vanguard Australia fund holdings

Vanguard Investments Australia

Full portfolio holdings for Vanguard ETFs.

Month-end snapshots, published with a multi-week lag by the issuer.

SPDR ETFs daily holdings

State Street Global Advisors

Full portfolio holdings for SPDR ETFs.

Daily, as published by the issuer.

ATO individual tax return instructions

Australian Taxation Office

The label definitions AMMA statement components are mapped to.

Annually, against the current income year's published instructions.

How look-through is calculated

"Look-through" means unwrapping a fund to the individual shares underneath it, then adding those up across every fund you hold.

01

Read the issuer's own holdings file

Each fund's holdings come from the file its issuer publishes — not from a third-party aggregator. Every security line is read with its weight as the issuer stated it.

02

Match securities to one canonical identity

Issuers name the same company differently. Each line is matched to a single canonical security so that a holding appearing in four funds is recognised as one company, not four.

03

Weight each fund by what you hold

Your dollar position in a fund is multiplied through that fund's weights, so a 9.2% holding inside a $50,000 position becomes the dollars you actually own of that company.

04

Total across every fund

The weighted lines are summed by security, which is what surfaces the concentration that no single fund's own factsheet can show you.

How we date a figure

Every data page carries an "as at" date. That date is the one the issuer published its file for — not the date we fetched it, and not the date you loaded the page. A fund whose issuer publishes month-end holdings will show a month-end date even if we refreshed this morning.

Where a page combines funds from different issuers, the figures are only as current as the oldest file behind them.

How bad data is caught before you see it

Issuer files change format, arrive truncated, or occasionally publish nonsense. Every incoming file is checked before it is allowed to replace what is already on the site — that it parsed, that its structure matches what the issuer published last time, that its weights total sensibly, and that it has not drifted implausibly from the previous snapshot. A file that fails is quarantined and the previous good data stays up. Stale but correct beats fresh but wrong.

What this can't tell you

  • Issuers publish on different clocks — a daily file and a month-end file sitting side by side means the older one sets how current a combined figure can be.
  • Weights are as at the issuer's publication date, not today. Markets moved in between.
  • Where an issuer discloses only part of a portfolio, the look-through covers only what was disclosed, and the page says so.
  • Funds that hold other funds are unwrapped only as far as the published files allow.

Corrections

If a figure looks wrong, tell us and we will check it against the source. Where we are wrong we fix the underlying data and the pages that read from it. See the editorial policy for how corrections are handled, or get in touch.

Underly publishes reference data compiled automatically from the sources above. It is general information only — not financial, tax or legal advice.