Test your investing idea before it costs you anything.
Describe a strategy in plain English in ChatGPT. Shadowfolio turns it into exact rules, backtests the last 12 months against a benchmark, then keeps a shadow portfolio of it every trading day from the day you save it, so you can come back and see how it would really be doing.
US stocks and ETFs, end-of-day prices. Hypothetical results only: Shadowfolio never gives investment advice, never picks investments and never places trades.
How it works
Say it your way
"Hold the 5 S&P 500 stocks with the best 6-month return, rebalanced monthly." Shadowfolio asks for anything you left open: what to trade, when to buy and sell, how often to rebalance, how to size positions.
See the last 12 months
Total return, max drawdown, Sharpe ratio, win rate and trades, next to a benchmark you choose, with the equity curve. Edit any rule in the card and run it again.
Track it from today
Save it and Shadowfolio updates a hypothetical 10,000 portfolio after every US market close. Ask "how is my strategy doing?" next week, or share a link.
Rules you can test
Trend filters
Own something only while it is above its 50- or 200-day average, or while a market fund is.
Momentum rotation
Each month, hold the top N of a list or of the S&P 500 by 1-, 3-, 6- or 12-month return.
Dips and breakouts
Buy on an RSI level or near a 52-week high; sell on another level, a stop loss, a take-profit or after N days.
Fixed mixes
Hold set percentages and rebalance weekly, monthly or quarterly. Park idle cash in a fund you name.
Honest about its limits
- Is this investment advice?
- No. Shadowfolio only runs rules you describe on past prices and shows what would have happened. It never recommends securities or strategies, and it can't trade.
- How realistic are the results?
- Trades fill at each day's close with a small cost you can change (0.05% by default). There are no taxes, no slippage beyond that cost, and no intraday prices. Index presets use today's members for the whole year, which flatters results.
- What does forward tracking add?
- A backtest can be tuned to the past. A shadow portfolio started today can't be: every day after you save it uses only prices that came after your decision.