01The problem
With one broker for ETFs, several platforms for crypto and a spreadsheet to tie them together, finding out what net worth is takes manual sums, and every sum makes the total harder to trust. Account statements, besides, don't say what you really own through the ETFs, or how much tax you would pay by selling today.
02How it is used
- You open the file, on a computer or a phone.
- The dashboard shows the picture: net worth, exposure by area and currency, companies owned through the ETFs, estimated tax.
- To update, you say one sentence. The assistant reads the prices from the agreed sources, recalculates, checks and saves a new version.
- Every update is a snapshot of net worth: the day-by-day history comes from there.
03How it is built
- Formata single HTML file, with no dependencies, servers or subscriptions
- Datapositions, transactions and history saved in the file itself
- Pricestaken only from sources agreed in advance, never searched for on the spot
- Checksa plausibility check before every price is written
- Taxestimated under Italian tax rules, with their asymmetries between ETFs and crypto
04Results
The plausibility check uncovered a mistake that had lasted for months: a token valued four times lower than the real figure, because the price came from a token with the same name on another network. Since then, sources are never guessed. Below is the real app, with made-up numbers and names.