Multi-broker

Tracking multiple brokers in one place (without a master spreadsheet)

DeGiro for cheap ETF orders. IBKR for options and US access. That app with the free share you never closed. Two or three brokers is a completely normal way to invest now, and it quietly breaks your overview.

Nobody plans this. Brokers compete on niches, cheap ETF orders here, US market access there, a sign-up bonus somewhere else, and rational people respond by opening accounts where each is strongest. The per-account decisions are all sensible. The portfolio-level consequence is that no screen anywhere shows you what you actually own. This piece is about that gap: what it costs, why the usual fix fails, and what a proper merge involves.

How everyone ends up here

The multi-broker portfolio is the default outcome of shopping around. You started somewhere, then a second platform did one thing better or cheaper, then a promotion handed you a free share on a third. Closing an account is paperwork with no deadline, so accounts don't get closed; they linger with a position or two aboard. Add a workplace scheme or a legacy account at a traditional bank and four platforms is unremarkable. Again: each step was rational. The sum just happens to be unreadable.

What fragmentation costs you

Each app shows its own slice with its own math. Your actual asset allocation, total tech exposure, total US concentration, real cash position, exists nowhere. Your dividends arrive in three interfaces. And any serious question ("am I beating the market overall?") requires mentally merging numbers that use different return definitions and different currencies. So nobody does it, and portfolio decisions get made per-app instead of per-portfolio.

The return-definition problem deserves a highlight, because it is invisible until you look. One app reports a simple gain on cost. Another reports a time-weighted figure. A third shows something it doesn't fully explain. These are different quantities that answer different questions, and averaging them in your head produces a number that answers nothing. Meanwhile the risk you most need to see, the same mega-cap stocks accumulating across three accounts through different funds, is precisely the thing a per-app view cannot show.

Why the spreadsheet dies

The master spreadsheet works for exactly one quarter. Different export formats, different currencies, fractional shares from one broker, position-IDs from another, you become the integration layer, unpaid, forever. The moment life gets busy, the sheet freezes in time.

Anyone who has built one knows the life cycle. The first weekend is enjoyable: columns designed, formulas written, a tab per broker, everything reconciled to the cent. The second month, one broker changes its export column order and the paste breaks. The third month, a dividend arrives in dollars and the currency handling turns out to be aspirational. By the fourth, updating the sheet is a chore competing with everything else in your life, and losing. The sheet's last update date becomes a small monument to good intentions, and the numbers in it drift quietly away from reality, which is worse than having no numbers, because you still half-trust them. The full autopsy is in spreadsheet versus tool; the pattern generalizes well beyond dividends.

The merge, done properly

The mechanics that matter when combining brokers: everything converts to one base currency at historical rates; the same cost-basis method applies everywhere (so per-position numbers are comparable); dividends from all sources land in one calendar; and the benchmark simulation uses your combined cash-flow history, because the S&P 500 doesn't care which app your money came from.

Each requirement earns its place. Historical-rate conversion is what keeps a dollar purchase from 2022 from being silently repriced at today's exchange rate, the core discipline of multi-currency tracking. A single cost-basis method means "up 12%" describes the same computation whether the position lives at DeGiro or IBKR, so comparing positions across brokers stops being apples and oranges. One dividend calendar turns three trickles of income notifications into one visible stream with a total. And the combined cash-flow history is what makes the benchmark honest: to know whether you beat the index, the simulation has to buy the index with every deposit you ever made, on the date you made it, regardless of which platform received the money.

The one-account objection

A fair question: why not just consolidate at one broker and skip the whole problem? For some people that is the right move. But the forces that created the fragmentation don't disappear, no single broker is best at everything, transfers between platforms can be slow or costly, and some accounts (a workplace scheme, a pension wrapper) cannot move at all. There is also a modest case for spread: platform outages happen, and not depending on a single login has its comforts. The realistic position for most investors is that multiple accounts are a permanent fact of life. The goal is not to eliminate the fragmentation but to stop it from fragmenting your information.

There is a middle path worth naming: consolidate the accounts that have stopped earning their keep, and merge the view of whatever remains. The dormant app with a single free share aboard is a candidate for closure; the two platforms you genuinely use for different jobs are not. Either way, the tracking question is the same. Even a portfolio that eventually lands at one broker still carries years of history from the others, and that history is what your long-term return is made of. Merging it once preserves it permanently.

What the merged view changes

The first merged look at a multi-broker portfolio is reliably educational. Allocation surprises come first: the tech concentration that three separate apps each showed as moderate turns out, combined, to be most of the portfolio. Then the forgotten positions surface, the free share, the leftover fund from a strategy abandoned in 2023. Then the useful questions become answerable at all: total return across everything, income across everything, and the headline verdict, whether the whole operation beats the S&P 500. Decisions improve for a boring reason: they are finally being made about the portfolio you own rather than the slice one app happens to display. Rebalancing, in particular, only means anything at the combined level.

One stream of events

BullBenchmark treats every broker export, DeGiro, IBKR, Trading 212, Robinhood, eToro, or any CSV via column mapping, as one stream of events. Upload each broker's file, get one portfolio: one allocation, one dividend calendar, one benchmark verdict. Your brokers stay separate. Your money stops pretending to be.

The workflow stays deliberately dumb: no logins, no linked accounts, no aggregator holding your credentials, just the export files each broker already produces, uploaded when you feel like updating, a design choice we defend at length in why we'll never ask for your broker login. Once a month, a file per broker, and the integration layer stops being you.

The setup cost is honest but small: find each broker's export screen once, and the routine afterward is a handful of downloads and uploads per month. If a platform's export screen is the obstacle, the per-broker walkthroughs on this blog cover the clicks. What you get back is the thing none of your apps could give you individually, a single set of books for your whole investing life, kept current for about the effort of paying one bill.

The first week of BullBenchmark is free, no card, upload the export you just downloaded and see where you stand.