Multi-Account Tracking & Data Quality

Spreadsheet Tracking

Definition

The use of a manually maintained spreadsheet to consolidate and track portfolio data from multiple sources.

Spreadsheet tracking is a flexible but maintenance-heavy operating model where portfolio truth depends on manual imports, formulas, reconciliations, and update discipline.

Why it matters

It gives full control over what is tracked and how. It also introduces manual error data lag and increasing maintenance burden as the portfolio grows.

What most investors miss

The gap between what the term means and how it is usually applied.

They underestimate the maintenance cost. A spreadsheet that works well at 2 accounts becomes a fragile and time-consuming system at 5.

How to read it

Treat a spreadsheet as a source of data discipline not a scalable portfolio tracking solution. The value is in the structure not the tool.

Multi-account lens

How this term reads differently across brokers and accounts.

Spreadsheet tracking is the most common multi-account workaround but it breaks under the weight of transactions dividends FX and multiple currencies.

Concrete example

What this looks like with real numbers.

Scenario

A portfolio covering 4 brokers, 3 currencies, and 58 positions takes 3 hours of weekly reconciliation. After 22 months, the spreadsheet has 14 formula patches, mis-classifies dividends in EUR as GBP, and understates one broker's cash by 4.1%.

What it reveals

Spreadsheets work well until they become the bottleneck. The real cost is not the hours — it is the confidence discount that accumulates as the model gets patched rather than rebuilt.

Diagnosis first, then workflow, then fit.

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