What if you had invested?
Pick a company, an amount and a year. We read the published monthly closing prices and do the arithmetic — including the part these calculators normally leave out.
Why we show you the falls
Every other version of this calculator prints one number: what the money became. It is true, and on its own it is misleading — because it quietly suggests the return was available to anyone who had the idea. It was not. It was available to people who held the position through every drop along the way without selling, which is a different and much rarer thing.
So we show the worst peak-to-trough fall inside your window, in money rather than percentages, and the worst twelve months. If you would have sold at that point — and most people do — then the headline figure was never yours to collect. That is the honest answer to “what if”, and it is more useful than the green number on its own.
What this is not
It is arithmetic on prices that already happened. It is not a forecast, not a recommendation, and not evidence that any company will repeat its past. A backward-looking calculator is at its most dangerous when it is used as a forward-looking one, and choosing the winners in advance is the entire difficulty that this page, by construction, skips over. See our financial disclaimer.
How the numbers are built
- Monthly closing prices from a public market-data API, split-adjusted.
- Purchase at the first available close on or after 1 January of the year you pick.
- Fractional shares assumed. No fees, spreads or taxes deducted.
- Dividends are not reinvested, so income-paying shares are understated here. For a company like Coca-Cola that is a material difference, not a rounding error.
- The S&P 500 comparison uses SPY over the identical window, so a company that listed part-way through is still compared like for like.