Compare Simulated and Live Trading

The two side by side

What paper trading proves

• The rules are configured correctly. The strategy fires when it should, at the strike and quantity you intended, with the stop and target attached.
• The signals work on live data. Backtests use clean historical candles; paper trading uses the live feed with its delays and noise.
• The platform and connection work. Logins, sessions and data subscriptions behave as expected.
• The strategy's recent behaviour matches the backtest. A few weeks of paper results should sit within the range the backtest's good and bad weeks suggest.

What paper trading cannot prove

• Fills. A simulated limit order fills when the price touches it. A real one may sit in a queue. A simulated stop fills at the trigger; a real one fills at the next available price. In thin option strikes, the difference can be several rupees per unit.
• Market impact. A simulated order does not move the market. A real order for many lots in a less liquid contract does.
• Margin reality. Paper trading may not block margin the way a broker does, so a position that runs on paper may be rejected live for insufficient margin, especially on expiry day.
• Rejections. Freeze quantities, banned securities, price bands and the broker's own restrictions appear only live.
• Your behaviour. Watching a simulated loss is nothing like watching a real one. Most of the damage traders do to a working strategy happens live, when they override it.

Why results differ

Expect live results to be somewhat worse than paper results for the same strategy over the same period. The difference comes from:

1. Slippage on entries and exits, the largest factor for intraday and options strategies.
2. Costs if the paper account did not model them fully.
3. Partial fills and orders that never filled.
4. Latency between the signal and the order reaching the exchange.
5. Manual interference, when the trader pauses, resizes or exits by hand.

If live results are much worse than paper, check the fills first: compare each live fill with the price the paper account assumed. If the fills match and results still differ, the trader is usually the variable.

How long to paper trade

Two to four weeks for a strategy that trades daily. Enough to see the strategy handle an expiry day, a trending day and a gap, and to confirm that the platform ran it without intervention. Longer paper trading does not prove the edge; that is the backtest's job. Our guide to backtesting vs forward testing explains the division.

Going live: a staged approach

1. Confirm the paper results match the backtest's expectations for the same weeks.
2. Check live margin for the intended size with the F&O margin calculator, including expiry-day additions.
3. Start with one lot. The purpose is to measure live fills and your own reactions, not to earn.
4. Set an [MTM stop loss](/mtm-stop-loss) across all positions at an amount you can lose without changing the plan.
5. Compare fills for the first twenty trades with the paper account's assumptions, and update the strategy's slippage estimate.
6. Scale in steps, doubling size only after a full month that matches expectations.
7. Keep a [trade journal](/trade-journal) of every override, with the reason. Overrides are the most common cause of live underperformance.

Paper trading in QuantPower

QuantPower's paper trading runs the same strategy definition that later trades live, on live prices from your connected broker account. Switching from paper to live changes the destination of the orders, not the rules, so there is no re-entry step in which errors creep in. Strategy performance reports show the paper and live records separately.

Mistakes in both modes

• Paper trading for months. After a few weeks, further paper results add little. Either the strategy goes live small or it goes back to the backtest.
• Trading paper with a size you would never trade live. Fifty lots on paper teaches nothing about one lot live.
• Treating paper profits as a forecast. They are an upper bound.
• Going live at full size. The first weeks live are a measurement, and measurements should be cheap.
• Changing the rules after a bad live week. Decide the review schedule in advance, such as monthly, and change rules only then.

Frequently asked questions