Three rows of hypothetical data
These prices were invented for this exercise; they are not historical returns. At the same time on day one, A is 100 and B is 200. On day two they are 110 and 202. On day three they are 105 and 206.
From day one to day three, A rises 5% and B rises 3%. Starting on day two instead, A falls about 4.545% while B rises about 1.980%. No observation changed; the selected window changed.
Rebase the starting point to 100
Calculate end price / start price × 100. With day one as the base, the final indices are 105 and 103. Subtract 100 to obtain percentage price changes. Enter 100→105 and 200→206 in the comparison worksheet to reproduce the result.
Starting on day two produces approximately 95.455 for A and 101.980 for B. Normalising price levels does not automatically align the observation window.
Freeze the window before moving the chart
TradingView's percentage comparison can use the first visible bar as its reference. Zooming or scrolling can therefore change the comparison baseline. Record the start, end, time zone and exact symbols before comparing screenshots.
Limit the conclusion to what was measured
A's price change exceeded B's by two percentage points in the first window. That is not a forecast or evidence that A is a better investment. Quote-currency effects require separate treatment when currencies differ. Price changes omit position size and fees and are not account returns.
Save a reproducible statement
“From __ to __ in time zone __, A changed __% and B __%; moving the start date produced __.” Put the sentence in the observation journal so the calculation can be repeated.