Before
you ask.

No. It is a simulator. There is no broker connection, no deposit and no order ever leaves your browser. Backtests, replay and live paper trading all use paper money.

From Coinbase Exchange's public market data. If Coinbase does not answer, the tool falls back to Binance's public data for the same pair. Under the Market panel it states what was loaded: the number of candles, the first and last date and the source.

No. Open the tool and an example is already running: an SMA crossover on two years of daily BTC-USD candles. You are asked for an account only when you save or share.

The strategy decides when a candle closes and the order fills at the next candle's open, moved against you by the slippage you set and charged the fee you set. Stop-losses and take-profits are checked inside each candle using its high and low. If a candle gaps through a stop, the fill is at the open.

Eight: SMA crossover, EMA crossover, RSI mean reversion, Bollinger band reversion, Donchian breakout, MACD signal cross, dollar-cost averaging, and buy & hold as the benchmark. Each has adjustable settings. You cannot write your own rules in code.

It runs the test for every combination of two settings, for example fast average 10 to 40 against slow average 25 to 100, and colors the grid by the result. One good cell surrounded by bad ones is a warning: those settings probably fit the past by chance. Sweeps are part of Pro.

You choose your settings while looking at only the first part of the history (in-sample). Then the strategy is judged on the rest, which it has never seen (out-of-sample). If it only works on the first part, it was fitted to the past. The split is part of Pro.

On Pro, the tool listens to Coinbase's public price feed, builds one-minute candles in your browser and runs your strategy on each candle close. If the live stream cannot be reached it checks prices every few seconds instead and says so in the status line. It runs only while the tab is open. There is also a recorded session of real trades so you can see it work without waiting.

Crypto pairs are always available. Daily bars for stocks and ETFs appear in the Market list only when the site operator has connected a stock data provider, so check the list in the tool.

Yes. Turn off "Long only" and a sell signal also opens a short position, backed by 100% collateral, with mirrored stops and targets. Dollar-cost averaging and buy & hold only buy.

On Pro you can download the trade list as a CSV file and create a public, read-only link to a result. The shared page stores the exact candles, so it shows the same numbers later.

Not necessarily. A backtest shows how a rule would have done on one stretch of the past, with assumptions about fills and costs. The more settings you try, the more likely the best one only fits that stretch by chance. Use the warnings, the sweep and the out-of-sample check, and treat every result as a hypothesis.

Yes. On a phone the tool is a single column with tabs for Setup, Results, Replay, Live paper, Robustness and Saved, and one main button pinned at the bottom.

Simulated results. Hypothetical performance has limits and is not a guarantee of future returns. Educational use only, not investment advice. StrategyLab does not know your situation and does not recommend any trade.