Declare which holdings belong in the total
A percentage weight needs a numerator and a total. A view restricted to invested assets differs from a view including cash. Preserve that scope with the displayed percentages rather than assuming every report uses the same denominator.
This case uses fictional CAD valuations and a closed teaching ledger. It does not authenticate an account, recommend an allocation or describe an institution’s reporting standard. Different currencies or valuation times would need additional evidence before pooling amounts.
Add a cash movement while holding asset values constant
Start with asset A valued at 60 CAD and asset B at 40 CAD, with no cash in the model. The asset weights are 60% and 40%. Now add a separately supplied 100 CAD cash deposit and keep both asset values unchanged. The whole-ledger total becomes 200 CAD.
Within that expanded scope, A is 30%, B is 20% and cash is 50%. An invested-assets-only view can still show 60/40 because its denominator remains 100. The difference between the reports does not prove that either asset price moved.
| Fictional view | Included denominator | Weights |
|---|---|---|
| Invested assets before deposit | 60 + 40 =100 CAD | 60%,40% |
| Whole ledger after cash | 60 + 40 + 100 =200 CAD | 30%,20%,50% cash |
| Invested assets only after deposit | 60 + 40 =100 CAD | Still 60%,40% |
A requested deposit is not automatically credited cash
The teaching calculation explicitly assumes the cash movement is included. An actual transfer request or pending notification does not establish that the relevant ledger was credited. Keep movement state and observation instant beside the balance used for the weight calculation.
If the cash belongs to another account or currency, it may be outside the chosen reporting scope. Preserve that distinction instead of adding a convenient amount to make the percentages sum as expected. A numerical total cannot resolve ownership or account-scope uncertainty.
Separate a price effect from a denominator effect
To attribute weight drift to prices, compare records with compatible holdings, cash-flow coverage, units and valuation times. A changed denominator can alter a weight even when its asset numerator stays fixed. A changed asset price can have a separate effect under the same scope.
Do not silently remove cash in one endpoint and include it in the other. If a report’s scope changed, identify that version change. Missing valuation or flow evidence can leave a complete attribution unresolved.
An internal sale differs from an external deposit
For another fictional no-flow ledger, reducing A from 60 to 30 CAD and adding 30 CAD of cash leaves the total at 100 when B remains 40. Its weights are 30%,40% and 30% cash. That is a different source of a cash-balance change from the earlier 100 CAD deposit. Do not classify every rise in cash as an external contribution. Keep the movement evidence and the comparison scope so a flow and an internal conversion are not confused.
Show both scopes and the open questions
A reproducible note retains the unchanged 60/40 asset values, the assumed 100 CAD credit and both denominator definitions. It can explain the 30/20/50 result without claiming that a market move caused it.
All amounts are invented. This guide does not calculate an investment return, recommend a rebalance or verify the linked offer’s performance. It complements a drift worksheet by exposing the reporting-scope decision before any interpretation.
The optional link below leads to this site's separate crypto signals and Telegram updates offer. The record method is usable without that offer. It does not independently verify the offer, establish country eligibility or turn the teaching example into an actual transaction.
Primary sources and scope
- Python documentation: rational arithmetic
Exact rational calculations independently check the invented arithmetic. No account, product or strategy is authenticated. Checked 2026-10-21.