Growth using historical data

This educational tool is free to use without an account. Change one input at a time, compare results and read the example and assumptions below. Results are illustrations, not forecasts or personal offers.

A chart displays data. Check what is measured, the units and the period before drawing conclusions.

Educational calculators only. Assumptions are not a quote or financing approval.

Using the result

Start with fictional amounts that are easy to check without a calculator. Write down the inputs and the first result, then change just one assumption. This helps you identify what caused the difference instead of changing several factors together. Check whether amounts are monthly or annual, which currency is used and which costs are included. Two decimal places do not make an assumption certain. Finally, explain the result in your own words, identify missing information and note what you would need to verify before using real money.

Explanation and example

Start with the title and source. A time axis may show days, months or years; the vertical axis may show price, percentage change or portfolio value. Read axis labels rather than assuming time follows the language direction. Lines show change over time; bars compare amounts; a candle shows open, close, high and low. Green alone is not enough information. Time range and scale change how dramatic movements look: an axis starting at 99 can exaggerate a move from 100 to 101, which is still 1%. Compare the same period and currency, and distinguish price charts from total return including dividends and costs. Past data is not a forecast or a trading instruction.

Practice example

Practice data for five days: 100, 110, 99, 105, 108. The total increase is 8%. From day 2 to 3, the drop is 10%: 11 divided by 110. A 10% rise followed by a 10% fall turns 100 into 99, not 100.

Plot the five points, label axes and units, and compare the whole period with days 2–3.

Check your understanding

What is the change from 100 to 108?

Does a rising historical line guarantee future gains?

Full lesson