Enter a coin, a date and an amount, then press Calculate.
01 Why this number can mislead you
This number is bigger than it feels like it should be — or smaller — for the same reason every look back at an old chart does: you already know what happened next. Hindsight bias is the tendency to treat past events as though they were predictable once you know the outcome. A trade that was a genuine coin flip at the time looks obvious in hindsight, and a trade that would have taken real conviction to hold looks easy.
That is exactly what this calculator cannot show you. It tells you what a single buy on a single date would be worth today — the shortcut version. It cannot tell you whether you would have actually held through the drawdown above, sold at the first scary red week, or never bought at all because the news that week was bad. Nobody trades with tomorrow's price already known.
FreeBacktest's replay is built to remove that advantage. It plays candles forward one at a time, hides everything after the current bar, and only reveals the next candle when you move to it — so a decision has to be made the way it actually had to be made, without the ending already known. If a past date on this page looks interesting, replaying it candle by candle is the way to find out whether the reasoning behind it would have survived, not just whether the ending was good.
02 FAQ
Do I need an account?
No. Everything on this page runs without signing up or creating an account.
Where does the price data come from?
Weekly close prices from Binance spot markets — the same historical data FreeBacktest uses for replay. It is not adjusted or estimated.
Why weekly candles instead of daily?
Weekly closes keep the calculation fast and the result stable, so a single day's spike or wick does not swing the answer. The backtester itself lets you drop down to much smaller candles.
Does this include fees or taxes?
No. This is a simple price comparison — what a fixed dollar amount would be worth today if converted at two weekly close prices. Real trading has exchange fees, spreads and taxes that this does not model.
Can I test more than a single buy-and-hold date?
Yes — that is what the backtester at /app is for. It replays candles one at a time and lets you place simulated market and limit orders, with stop-loss and take-profit, against real historical data.
Which coins and dates can I check?
Seven coins quoted in USDT on Binance spot: BTC, ETH, SOL, BNB, XRP, ADA and DOGE. Weekly data starts in late December 2019 for most of them; SOL's starts in August 2020, when it began trading.
FreeBacktest is an educational tool. Nothing here is investment advice. Past results — real or simulated — do not predict future results.