Reading historical portfolio value in the base currency
Attach explicitly reviewed CNB reference-rate histories to the original daily states. Positions, cash, original prices and gaps stay inspectable; a change in value alone is not investment return.
1. Prepare the original history first
In Portfolio, open Historical value and switch from Unified history to Original stock view. Prepare completed UTC days and review the actual dated positions, cash and assigned stock sources, including positions closed today. Conversion uses that exact result without changing its quantities, prices or original export.
The base currency comes from your portfolio. This workflow supports exact CZK, EUR and USD units; it does not infer a rate for GBP, GBp, USDT or other unsupported units. The local FX dataset is currently scoped to 2026. Up to seven days before the interval are loaded, but never earlier than 1 January 2026; a missing older reference remains a gap. An interval outside the supported year disables loading with an explanation.
2. Load and review both rate histories
Choose Load original daily fixings. This prepares two separate original inputs: CZK per 1 USD and CZK per 1 EUR. The window covers the selected interval and up to seven preceding days for explicitly carried references. Loading inputs does not yet calculate the financial conversion.
Review the units, returned time window and both original results. Then choose Apply historical conversion. A single current fixing is not applied to the whole past interval.
3. Distinguish the complete total from the known portion
Historical value in base currency uses the original value of every dated position and cash balance exactly once. A complete total is available only when every member is covered; otherwise the known portion is labelled and each unavailable part has a reason. An unknown value is not zero.
A member already in the base currency needs no unrelated rate. Conversions and totals use exact original values; displayed amounts are rounded independently, so summing them may differ from the total in the final decimal places.
4. Open a day and its original fixing
The chart and complete date table use the same result. Selecting a day from either opens the same detail with positions, cash, gap reasons and rates. The original fixing date and its age stay distinct from the valuation day.
The latest original fixing no later than the day is used, with an age limit of seven days. A weekend may carry a real earlier reference; it does not create a new weekend observation. If the latest point is null, suspect, retracted or nonpositive, that conversion stays unavailable rather than silently falling back to an older usable value.
5. Verify the same inputs and download the whole result
Verify the same historical conversion renews access to the same original result and inputs. A new session, changed ledger or revoked access cannot expose old financial values without fresh admission. A late reply cannot overwrite an edited draft.
Whole base-currency history JSON or CSV contains the full interval, every member, the original financial history and both complete FX inputs. Selecting a day does not shorten the export. A file preserves methodology and provenance, not a login session or live authorization.
6. Value is not return or then-known knowledge
The curve reconstructs value using the current recorded ledger and sources retained now. A later-recorded event or newly captured historical reference does not prove what the application knew then. A fixing is a reference rate, not an immediately tradable quote.
Deposits are not profit, and a change in value is not TWR, CAGR or performance drawdown. Conversion also does not determine historical FX PnL, tax or missing crypto history. Those methods need their own suitable inputs and remain separate.
This is a guide to Datisto. Private features require sign-in and access to your own data. Personal models use your assumptions; availability and permitted use of source data are checked with the particular result. This is not investment advice.