← Folionomiq Free preview

How every figure is measured

Every number this tool reports, the method that produced it, and what it will not support. If something here is wrong, write and say so — [email protected]. The whole product rests on this page being true, and one person reads that address.

The window

Every figure is measured over the stretch where all of your holdings have prices — the days where any one of them is missing are dropped for the whole portfolio, so that every holding is compared over the same days.

The consequence is worth stating plainly, because it surprises people: the youngest holding sets the start. Add a fund launched eighteen months ago to a book you have held for twenty years, and every figure on the page is measured over eighteen months. The window is printed beside the reading everywhere it appears, for exactly this reason.

The prices

End-of-day closing prices from public sources. No intraday data, no quotes, nothing streamed: this tool measures what a portfolio has done, and the close is the right resolution for that.

Holdings quoted in another currency are converted into your base currency at each day's rate, so the reading is what you actually experienced rather than what the asset did locally. The gap between those two is itself reported, as currency exposure — and the hedged leg there is a perfect, costless hedge, which a real one is not.

A ticker that will not load is named, never silently dropped. A portfolio tool that quietly analyses four of your five holdings is worse than one that refuses to answer.

Every figure

The code beside each name is the number the report cites it by, so a report you have copied and this page can be read side by side. The word after it says what sort of thing the figure is — almost nothing here is simply observed:

Read off the engine at build time, by running it over six example portfolios. Several figures are conditional and appear only where they mean something, so this is the union of what those portfolios produced, not a fixed list.

F1Holdingsobserved

count of positions

F2Effective betsestimated

Meucci effective number of bets on a Ledoit-Wolf shrunk covariance, PCA basis

Describes how many independent directions the risk occupies. It is not a forecast of loss and does not predict a drawdown.

F3Risk in the largest shared directionestimated

variance share of the leading principal component

This is commonality, not a fault. A diversified equity book is MORE driven by one shared direction than a single stock is, because diversifying is what removes the idiosyncratic part.

F4Annual returnreplayed

compounded, monthly rebalancing

Past window only. Says nothing about the next one.

F5Volatilityreplayed

annualised standard deviation

F6Return per unit of riskreplayed

Sharpe ratio, on returns in excess of the base currency's 3-month rate

Noisier than it looks: on sixteen years of a 60/40 book the 90% interval around this figure is about a Sharpe of 0.5 to 1.4. Read it as a band, not a score.

F7Worst fall on recordreplayed

largest peak-to-trough decline inside the window

The worst fall *in this window*. A longer window would very likely contain a worse one.

F8Holdings leading that directionestimated

largest absolute loadings on the leading component

Loading signs are fixed so the largest is positive; a negative loading means that holding moves against the others.

F11–F15Each holding: money and riskestimated

Euler risk contribution on the same shrunk covariance as F2

The ratio is the finding. A weight alone cannot say whether a position is large, because that depends on everything else held.

F20Risk, earlier stretch then later stretchreplayed

the last 252 trading days against the 252 before them

F21What changed the riskestimated

exact additive split of the change in variance into individual volatilities and co-movement, averaged over both orderings (Shapley)

Today's weights are held fixed across both stretches. This is what the MARKET did to the book you hold now — not a history of the book, which this app does not store. Reading it as 'my trades caused this' would be exactly backwards.

F22Average pairwise correlationestimated

mean of the off-diagonal shrunk correlation matrix, each stretch

What is not computed

No forecast of returns, losses, prices, or the probability of any of them. No recommendation to buy, sell, or hold, and no suggested allocation.

That is not modesty, and it is not a gap waiting to be filled. Every figure above is arithmetic on prices that already happened, and each one carries the window it was measured over and the limit of what it supports. A forecast would be a different kind of statement, made on a different basis, and it is deliberately not one this product makes.

What is known about you

Your portfolio. It is kept in your own browser and nowhere else. There is no account and no sign-up. Holdings are sent to the server to be measured and are not stored there — which also means that if you clear your browser data, they are gone, and we cannot restore them. What is kept is a pooled count of which funds are combined, each weight rounded to a band of ten points, with the month and the country; nothing about a combination is shown until fifty measurements share it (the terms say exactly what).

What changed since last time. A few numbers from each visit — how many independent bets, how much of the risk sat in one direction — are kept beside your portfolio, in the same browser, so a later visit can say what moved. At most two dozen readings, no holdings and no amounts among them, and none of it is ever sent anywhere. There is a button under every view in the app that erases it.

The counting. Page views are counted, in aggregate. Each day a random secret is generated, held in memory and never written down; a visitor's address is hashed with it to make a short identifier that distinguishes one reader from another for that day only. The secret is discarded when the day rolls, so yesterday's identifiers cannot be matched to today's or reversed to an address. What is saved is the count, not the identifiers. No cookies, no analytics vendor, no third-party script anywhere on this site. The full notice, including what happens if you write to us, is at /terms.

What this is

A free, non-commercial preview. Nothing is charged, nothing is sold, no price data is redistributed or offered for download. It is early: expect rough edges, and expect figures to be added rather than removed. Questions, corrections and complaints all go to the same place: [email protected].

Descriptive portfolio analytics for research and education. Not investment advice; no recommendations and no price predictions. Read a finished analysis at /examples, or measure your own at the app. The terms this is offered under, and what happens to your data, are at /terms.