What the calculator is doing
AltPath answers a simple question with real historical prices: if you had put a specific amount into a stock or ETF on a past date, what would it be worth now (or on a date you choose)?
It is a learning tool. The numbers describe what did happen in markets, not what will happen next. Use the output to build intuition about volatility, time in the market, and how dividends or regular contributions change the story.
Headline gain or loss
The large figure at the top is your net profit or loss in cash terms for the scenario you entered. For stocks with dividend history, we split price change and dividends so you can see whether return came mostly from the share price moving or from income paid along the way.
Percentage return puts the same story in relative terms. A £500 gain on £1,000 invested is a 50% return; the same £500 on £20,000 is 2.5%. Both matter when you compare strategies.
Buy price vs current price
Buy price is what the asset cost on your start date (or the average entry for recurring buys). Current price is the latest historical quote we can fetch for your end date.
If you chose a currency different from the stock's listing currency, we convert using historical FX where available. Small rounding differences are normal.
Charts and benchmarks
The price history chart shows how the asset moved across your holding period. Benchmark and compare sections let you line up another ticker or index to see whether your choice outperformed or lagged a simple alternative.
Cash and inflation sections put the result in context: staying in cash or losing purchasing power to inflation is a useful baseline when you are thinking about long-term investing.
Common mistakes to avoid
Keep these in mind when you interpret any calculator output.
- Treating a lucky five-year window as proof you can pick winners.
- Ignoring fees, taxes, and spread - our figures are before your personal costs.
- Assuming dividend history repeats exactly.
- Using very short periods where one news event dominates the result.
