What a fixed buy of Bitcoin, Ether or Solana every day, week or month would have done over the period you choose — units, average cost, value today, the worst drawdown you would have sat through, and the lump-sum comparison. A replay of a habit, not a prediction.
It tells you what discipline would have produced over one specific stretch of history, including the drawdown you would have had to sit through without selling — the number most people skip and the one that actually decides whether they keep going. It does not tell you what the next year will do. Move the start date by six months and watch the result change; that variance is the honest lesson.
The lump-sum line is there to keep DCA honest. In a market that mostly rose, investing everything on day one ends ahead because the money was working longer. In a market that fell first, DCA ends ahead because later buys were cheaper. Neither is "the right strategy"; DCA is the one most people can actually execute, which in practice matters more.
Accumulating a long-term position on a schedule is a way of not making a timing decision you are not equipped to make yet. It is a savings behaviour, and it belongs in the part of your capital that is not trading capital. Trading — entries with a stop, a size and a target — is a different activity with different rules, and averaging down into a losing leveraged position is not DCA; it is refusing to take a stop. Lesson 3 draws that line, and the position size calculator governs the trading side.
On each scheduled date the calculator spends the amount you set at that day's closing price (after the optional fee), adds the units bought, and records the total invested and the portfolio value. Average cost = total spent ÷ units. Drawdown = the largest fall in portfolio value from any earlier peak, measured on closes. The lump-sum line invests the same total on the first day at that day's close. Prices are daily closes in USDT; spread, withdrawal fees and taxes are not included.
What is dollar-cost averaging (DCA)? Buying a fixed dollar amount of an asset at a fixed interval — every week, say — regardless of price. You buy more units when the price is low and fewer when it is high, so your average cost tends to sit below the average price over the period. It removes the timing decision; it does not remove the risk of the asset falling.
Is DCA better than a lump sum? Not reliably. In a rising market a lump sum at the start usually ends ahead because more money was invested for longer; in a falling or choppy market DCA usually ends ahead because the later buys were cheaper. The calculator shows both for the period you choose. DCA's real advantage is behavioural: it is easy to keep doing.
Is this calculator a backtest of a trading strategy? No. It replays a savings habit against real historical closes. Past prices do not predict future ones, and the same schedule started a year earlier or later can look completely different — try shifting the start date.
Where do the prices come from? Daily closing prices from Binance's public market-data feed (USDT pairs), fetched through our server and cached; CoinGecko as fallback. Fees and spread are not included unless you enter a fee rate.