How to Track a Multi-Broker, Multi-Currency Portfolio Without Losing Your Mind

Most portfolio-tracking advice assumes you have one brokerage account, in one currency. That's rarely how it actually goes. You opened an account with one broker years ago. Then you moved somewhere and picked up a local one for tax reasons. Then you started buying crypto on an exchange that isn't a "broker" at all. Somewhere in there, you ended up holding positions priced in three different currencies.

None of this is unusual. It's also exactly where spreadsheets — and most simple tracking apps — quietly start lying to you.

The problem isn't tracking each account. It's reconciling them.

Every broker will happily show you your balance in isolation. What none of them will do is tell you your total exposure to a single stock if you happen to hold it in two different accounts, or your true overall return once currency movements are mixed in with the investment's own performance.

A spreadsheet can technically hold all this data. The problem is what it takes to keep it accurate: every trade has to be entered by hand, in the right currency, converted at the right historical exchange rate — not today's rate — and every broker exports its trade history in a slightly different format, so "just copy-paste it in" rarely works cleanly for long.

Currency conversion is where the real damage happens

Here's a mistake that's easy to make without noticing: if you bought a stock in GBP two years ago and you're converting your whole portfolio to USD today, using today's exchange rate on that old purchase silently distorts your actual return. Your gain or loss should reflect the FX rate at the time of each transaction, not a single blanket rate applied retroactively to everything.

This is a small detail that compounds into a genuinely wrong number if you're not careful — and it's exactly the kind of thing that's easy to get wrong in a spreadsheet and easy to not even notice you got wrong, because the resulting number still looks plausible.

What actually needs to happen for this to work

• One single transaction log, with every buy, sell, and dividend from every broker, tagged with which broker and which currency it happened in.
• Historical FX rates applied per-transaction, not a single current rate applied to your whole history.
• A display currency you can toggle, separate from the currency each position was actually bought in — so you can think in one currency without losing the original transaction detail.
• Consolidated position sizing, so if you hold the same stock across two brokers, you see it as one position when it matters (like checking concentration risk), not two disconnected line items.

The realistic alternative to "just be more disciplined with the spreadsheet"

The honest truth is that this isn't really a discipline problem. It's a data-modeling problem — the kind of thing that's tedious to build correctly and easy to get subtly wrong, which is exactly why most people who try to DIY it in a spreadsheet eventually give up or stop trusting their own numbers.

For the practical checklist version of this — the actual steps, in order — see how to track a portfolio across multiple brokers. And when you move holdings between brokers, see how to record broker transfers and stock splits without wrecking your cost basis.