Portfolio Look-Through: What a Portfolio Actually Holds

What a portfolio actually holds — and what it did

A list of tickers hides its own shape: one position quietly grows into half the total, three funds turn out to overlap, everything sits in one currency. The Allocations tab redraws a portfolio as weights — by holding, sector, industry, country, currency and type. Every new Slowio account starts with a small sample portfolio — two stocks and three ETFs. It makes an honest test subject, because every figure below can be reproduced on the Portfolio page.

One holding — Apple Inc. — has grown to 71.9% of the whole portfolio. That is exactly the kind of fact a table of tickers keeps to itself. The tab’s concentration cards turn that into one number: these five holdings behave like 1.8 equally-weighted positions.

What’s inside the funds? 3 of the 5 holdings are funds — 18.3% of the portfolio the pies above can only label “ETF”. The tab’s look-through opens them up: stocks count directly, funds are split into their own published sector weights.

The point: this portfolio’s real technology exposure is 75.9%, not the 71.9% the Apple position alone suggests. The S&P 500 fund quietly adds 4.0 points more of the same bet — about 38% of that fund is technology stocks. The remaining 7.8% is the only part of the portfolio that is truly not an equity bet. The look-through also works by country and region, on any portfolio or watchlist.

The same tab adds treemap, sunburst and donut views, a geographic exposure map, and a full concentration panel (HHI, Lorenz curve, Gini) — the anatomy of any portfolio or watchlist.

“Is it up?” is really three questions: how much cash went in, what it is worth now, and how the gap between the two built up over time. The Performance tab answers all three at once — dividends included, on the same sample portfolio:

The tiles above the chart condense it to the headline numbers — including the 1,916 USD of dividends a price-only view would miss. It also keeps the uncomfortable part: early on, the portfolio spent 39 days worth less than the cash that had gone in — at the worst point 565 USD under water (Oct 2023). The chart’s Unrealized Losses layer records those stretches — here a sliver of red barely visible at today’s scale — the kind of detail a summary row erases.

Who did the work? A portfolio return is an average, and averages hide their parts. The tab’s Positions view splits the 90,376 USD result into one bar per holding — price moves and dividends counted together:

One holding — Apple — produced 79% of the whole result. And the quietest bar teaches the loudest lesson: TIP’s price actually lost 39 USD — its 208 USD of dividends is the only reason it shows green. The same view adds per-position weights, concentration analysis and a sortable table.

The same tab overlays a benchmark of choice, splits realized from unrealized results, isolates the currency effect for holdings in foreign currencies, and breaks returns down per period.

Slowio is an educational research tool, not financial advice. Figures are computed from Slowio’s data snapshot at build time and may not reflect the latest market data — nothing in this email is a recommendation to buy or sell any security. Do your own research.