Demo vs Live Trading: What Paper Trading Proves
Paper trading validates strategy logic — not fills, slippage, or your own psychology. How to graduate safely.
Перевод пока недоступен — показан английский вариант.
What paper trading is good for
Paper (demo) trading runs a strategy against live market data with simulated fills. It answers the logic questions cheaply: does the signal fire when it should, do position sizes compute correctly, do risk limits trigger, does the agent behave through volatility — all without risking capital.
Every major venue supports this workflow: Binance maintains a dedicated spot testnet, and both dYdX and Hyperliquid document testnet environments for practicing perps mechanics before mainnet.
What paper trading cannot replicate
Simulated fills are optimistic. Paper engines typically assume mid-price or top-of-book fills with no market impact; live trading pays the spread, suffers slippage on size, and gets partial fills in fast markets. Fees and funding are often approximated or ignored.
The bigger gap is psychological: clicking through a 20% paper drawdown is trivial; watching real capital do it triggers intervention — widening stops, doubling down, disabling the agent — which invalidates the backtest you just ran.
A graduation checklist
Promote a strategy to live capital only when: it is profitable net of realistic fees and slippage assumptions over at least dozens of paper trades; its worst paper drawdown is a fraction of what you could tolerate live; risk limits (per-trade loss, daily loss, kill switch) are enforced by the platform, not by willpower; and you start at minimum size — paper size means nothing until live fills confirm the edge.
JW3.ai's paper mode exists for exactly this pipeline: validate agent behavior in simulation, then deploy the same agent live with identical risk limits and human-approval gates.
Frequently asked questions
Is paper trading worth it?
Yes for validating logic, sizing math, and risk-limit behavior. No as proof of profitability — simulated fills ignore spread, slippage, and market impact.
Why do strategies that work in demo fail live?
Optimistic fills, ignored fees and funding, and trader psychology: live drawdowns trigger manual interference that the paper test never modeled.
How should I size my first live trades?
Minimum size with hard platform-enforced loss limits. Scale only after live fills confirm the edge paper trading suggested.