ETF Look-Through

Live

Finance / Tool

See the actual stocks behind your ETFs - and how much of each you really own.

ETF Look-Through in dark mode - a $23,340 demo portfolio of XEQT, VOO, QQQ and VFV decomposed into 105 stocks, with NVIDIA on top at 6.78%, colour-capped summary tiles, a top-exposures donut, a market-mix bar, and the light/dark theme toggle up top

What it does

Index investors hold the same stocks many times over without seeing it - the Microsoft inside VOO is also inside VFV and XEQT. ETF Look-Through decomposes every fund in your portfolio into its published holdings and adds up the overlap, so before you buy a stock directly you can see exactly how much of it you already own, which funds it comes through, and what share of your money sits in each market.

Current features

Portfolio builder - pick from a curated catalog of 27 popular US and Canadian ETFs, or add direct stock positions that merge into the same look-through
All-in-one funds unwrapped - XEQT, VEQT, XGRO and VGRO decompose through their underlying funds, bond sleeves and all
Auto-add any ETF by ticker - the page fetches a fund's top-25 holdings and live price on the fly and publishes it to a shared community catalog (Firestore), so the next visitor gets it too
Live prices - stockanalysis.com quotes direct for US listings, Yahoo through CORS proxies for TSX ones, ECB for the USD/CAD rate, auto-refreshing when over an hour stale; every price stays hand-editable
Answer card - search a ticker and get the direct answer: you already own $X of it, through these funds
Donut of top exposures, market-mix bar (US / Canada / international / emerging / bonds), and a searchable holdings table with per-fund source chips
No accounts, no build step - entries persist in the browser and export/import as JSON

Tech stack

Vanilla JS
SVG
Firebase Firestore

What I learned

The hard part was never the math - it was data honesty. Public holdings pages itemize only a fund's top ~25 positions, so the UI budgets for what it does not know: an explicit coverage number, visible 'smaller holdings' rows, and a warning when an auto-added fund is really a fund of funds. Also a practical lesson in hosting: the page began as a sandboxed Claude artifact that could not fetch anything, and every capability it gained since - live quotes, auto-add, the shared catalog - came from moving to real static hosting.

What's next

Curated look-throughs for popular funds the community adds
A first-party quote proxy so TSX prices stop depending on public CORS proxies