Paper trading runs your bot on virtual money at real prices. Live results usually come out worse, because a simulated order doesn’t have to find a real buyer or seller. Treat paper trading as a test of whether the bot behaves as you expect. It doesn’t tell you what you’ll earn.
Where the gap comes from
| Cause | On paper | Live |
|---|---|---|
| Fills | Often assumed at the price you asked for | You get what the order book offers |
| Slippage | Zero, or a set number | Grows with order size and fast markets |
| Limit orders | May count as filled when the price touches them | You wait in the queue and may get nothing |
| Partial fills | Rare | Common on thin coins |
| Delay | None | The price moves while the order travels |
| Rejected orders | Don’t happen | Below minimum size, not enough balance |
| Your own hands | You leave it alone | You may stop it after a loss |
TradingView’s broker emulator shows how much this depends on settings. By default it can fill a limit order at the exact price requested, and orders are executed on the bar where they were created. Both settings are optimistic compared with a real market.
The strategies most affected
Bots that trade often and aim for small gains suffer most, because slippage takes a larger share of each trade. Slow strategies on large coins suffer least.
How to measure the gap
- Run the same rules on virtual money and with a small live amount at the same time.
- After 20 or more trades, compare each pair: entry price, exit price and fees.
- Work out the average difference per trade.
- Subtract that difference from your backtest and see whether the idea still makes money.
If it doesn’t, you’ve spent a small amount to avoid a large mistake.
What to do with your paper results
Use them to catch problems: a bot that buys at the wrong moment, sizes orders badly or never exits. Don’t use them to work out income. In Tradenos, Practice runs your bot on virtual money at real prices, and results can differ once it’s live because real orders can fill worse.
Before going live, read how to set up an API key safely.