How to forward-test a strategy without a brokerage account
Forward testing (often called paper trading) means fixing your rules today and recording what they would have done on every trading day after that, which a backtest can't fake. Shadowfolio does it inside ChatGPT: save a strategy and it keeps a hypothetical 10,000 shadow portfolio from the latest close, updated after every US market close, with no brokerage account and no real money.
Updated · The Open Apps, Inc.
Step by step
- Settle the rules. Describe and backtest the strategy first so you know exactly what it does.
- Save it. Say "save it and track it daily". Tracking starts from the latest settled close.
- Let it run. After each US close, Shadowfolio applies your rules to that day's prices and records the result. Days already recorded never change.
- Check in. Ask "how is strategy #1 doing?" to see the return since you saved it, the drawdown, the benchmark over the same days, current holdings and recent simulated trades.
- Share or stop. Make a share link to show the record, or say "stop tracking strategy #1" to delete it.
Why a forward test matters
It's easy to tune a backtest until the past looks good: try enough variations and one will. A forward test is immune to that, because the rules are fixed before the prices exist. If a strategy only shines in its backtest, the forward record usually shows it within weeks or months.
Ways to do it
| Shadowfolio shadow portfolio | Broker paper-trading account | Spreadsheet log | |
|---|---|---|---|
| Account needed | No; works inside ChatGPT | Yes, usually a brokerage sign-up | No |
| Follows rules automatically | Yes, after every US close | No: you place each simulated order | No: you update it |
| Intraday fills | No: daily closes only | Yes | Whatever you record |
| Benchmark alongside | Yes, over the same days | Rarely | If you add it |
Paper-trading accounts are better for practising order entry and intraday timing; a shadow portfolio is better for checking whether a rule-based idea holds up.
Use it in ChatGPT
Add Shadowfolio in ChatGPT (coming soon to the plugin directory), then say:
- Save my SPY trend strategy and track it daily from today.
Shadowfolio runs only the rules you describe. It never suggests investments, never gives advice and never places trades.
Questions
- Is forward testing the same as paper trading?
- Close: both use no real money. Paper trading usually means placing simulated orders by hand; a forward test applies fixed rules automatically. Shadowfolio does the second.
- When does tracking start?
- At the latest settled US close when you save, with a hypothetical 10,000.
- What if I change the rules?
- That's a new strategy with its own record; the old record stays as it was until you delete it.
- Can it trade for me?
- No. Shadowfolio never places trades and never connects to a broker.