Precomputed toggle variants are the finished result sets Fincanva computes for every combination of the three simulation assumptions — Costs & interests, Taxes and Reinvest profits — inside one single backtest, so flipping a toggle selects an already-computed result instead of starting a new one. Three on/off switches make eight combinations, and one backtest fills them.
Also seen as: toggle combinations, assumption variants
How does Fincanva handle it?
- The toggles read a variant; they never queue a backtest, so they work identically on an old result and a fresh one, and never change the strategy's status.
- The rates behind the toggles are a different kind of change: editing a cost or tax rate is a settings change, which makes the strategy read Needs re-run and takes effect only after a re-run.
- Reinvest profits also selects which annualized figure is shown — CAGR when it is on, AAGR when it is off — and that swap is instant for the same reason.
- The Positions view is always served from the reinvesting, costs-off, taxes-off variant, whatever the toggles above the backtest results say: it answers "what would this strategy hold now", not "what did it net historically" (Positions forced assumptions).
- Because the variants belong to the backtest, a strategy whose result is reused rather than recomputed (shared compute) arrives with all of them in place.
What does it look like in practice?
You run a strategy once, with both cost and tax rates configured in your settings. The results open on the default view — gross of costs and tax, profits compounding. You flip Taxes on: the return, the annualized figure and the monthly table all drop to their after-tax values at once, because that variant was computed in the same backtest. You flip Reinvest profits off and the headline metric switches from CAGR to AAGR just as fast. Then you open Settings and change the capital-gains rate from 26% to 20%: nothing on the page moves, the strategy reads Needs re-run, and the new rate only appears after you re-run — the eight variants belong to the backtest that produced them, and a new rate needs a new one.
Why does flipping an assumption toggle update instantly?
Because the result you switch to already exists. The three toggles are not inputs the backtest is waiting on — they choose which finished variant is displayed, so switching one is a read, not a recomputation. A backtest therefore produces the gross view and the after-cost, after-tax and non-compounding views together, and the results page moves between them with no queue and no progress bar. That is why the after-tax curve appears the moment you ask for it.
Why are there eight variants?
Three toggles with two states each give eight distinct combinations. Costs & interests, Taxes and Reinvest profits are each either on or off, and every way of setting the three of them together is one variant:
where: each factor is one assumption toggle with two states, on and off, and 8 is the number of distinct combinations of the three. All eight are produced when both costs and taxes are configured in your settings; fewer are produced when one of those sides is not configured, because a side with nothing set has nothing to switch between. Either way, every combination the app lets you select has a finished result behind it.