Known terms and assumptions
Separate confirmed contract conditions from estimates. A fixed rate for one placement does not fix the next placement. The revision rule matters as much as the initial number.
Sequential accumulation
Without flows, F = P × (1 + i₁) × … × (1 + iₙ). Do not add rates or use a simple average when income remains invested. With payments, recalculate after each operation because money arriving at different times receives different later factors.
Two fictional paths
For 200,000 roubles, six months at 1% and six at 0.4% gives 200,000 × 1.01⁶ × 1.004⁶ = 217,450.55. Keeping 1% for twelve months gives 225,365.01, a different model. Swapping blocks changes nothing without cash flows, but a mid-term deposit participates only in later rates. Market assets also add repricing and loss risk.
Ranges and errors
Show unchanged terms, a decrease and a different revision date; do not call them probable without probabilities. Do not mix effective annual and monthly rates without conversion, extend promotional periods or capitalize growth twice. Preserve old scenarios after actual conditions change.
Forecast versus recording
Replace planned rates with actual rates while keeping planned contributions, then replace contributions with actual ones. This separates condition variance from personal cash movements. Do not call the whole gap lost income if planned contributions were never made. Record terms from the [conditions comparison card](/guides/comparing-deposit-conditions/) before extending beyond the confirmed contract.