BorderFolio/Blog

Blog

Long-form writing on the two things this product exists for: measuring what a portfolio actually did, and what crossing a border does to the answer. No market calls, no fund picks — method, arithmetic and worked examples.

31 August 2026 · 16 min read

My broker told me I’d made $18,000. It took me months to work out what that number meant. Why this product exists. Years of contributing, a six-figure portfolio built by deposits rather than by any clever trade, and a dashboard that could price it to the cent but never explain it — plus what happens to all of it when you live in one country, run a business through another, and hold funds registered in a third. Founder storyContributionsCross-borderFIRE

30 August 2026 · 12 min read

How to track portfolio performance: XIRR, TWR and the metrics that matter Your balance is up $15,880 and you deposited $12,400 of it. This walks through every metric that tries to answer "how did I do" — the contribution split, total gain after costs, realized vs unrealized, and the two annualised returns that can disagree by 45 percentage points on the same year. XIRRTime-weighted returnPerformanceWithholding tax

Reference documentation

The methodology pages carry the formulas the product actually runs, with their inputs, assumptions and limits stated in full.

True return methodologySeparating deposited capital from market movement: the identity, what is measured independently, and what the method cannot see. Withholding methodologyThe two-step model — withheld at source, then taxed at residence — and how each per-instrument rate is resolved. Contribution trackerHow contributions, pace, streak and gaps are recorded from statements. Broker statement importSupported formats, what gets extracted, and how overlapping statements are de-duplicated.

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