The short answer: backtest first. Then paper trade the same rules. Each test can find a different kind of flaw.

What does a backtest check?

A backtest runs clear rules on old market data. It shows when the rules would have fired. It also shows the trades and the path of the test.

The setup matters. The chart can change when you change the time frame, test dates, trade size, fees, stops, or data. A neat score does not make a weak test safe.

What does paper trading check?

Paper trading watches the same rules as new prices arrive. No real money is at risk. It can show if signals come at the right time and if the work stays clear.

Paper trades are still a model. Fills, speed, fees, and cash needs may not match live trades. Paper results do not prove what will happen next.

BacktestHistorical behavior
Paper tradeForward observation
Live tradeReal execution risk
Backtest riskOverfitting
Paper riskSimulated fills
Shared needClear rules

Which test comes first?

Start with clear rules. If the idea still uses words like “soon” or “strong,” first write rules a test can follow. Then run a backtest. Check the trades, not just the score. If the test holds up, paper trade the same rules.

A good backtest is not a pass to skip paper trading. A slow paper test does not mean the backtest was wrong. The two tests use different data and find different flaws.

Backtest the logic. Paper trade the process. Confuse neither with a promise.

Use this five-step test

  1. Write the rules.Name the symbol, time frame, entry, exit, trade size, and risk cap.
  2. Run the backtest.Read the trade list. Look for gaps and odd trades. Use the backtest validation checklist before you trust the score.
  3. Push on the result.Make small, fair changes. See if the result falls apart. Save new data for an out-of-sample test.
  4. Paper trade the same rules.Do not hide a rule change between tests.
  5. Review before live use.Live trading is a new risk choice. It is not the next step by default.

What if the tests do not match?

Check the setup first. Did both tests use the same rules, symbol, time frame, trade size, and order time? Did the paper test have enough trades? Did the market change?

Check fills and costs too. The trading-cost guide shows how spreads, fees, slippage, and size can change a test. Write down the gap. Do not change rules just to make the two tests match.

Why a connected workspace helps

TradeLab keeps the rules, test setup, backtest, trade list, and paper controls in one flow. That helps you test the same idea at each step.

Risk disclosure

Backtests and paper trades are models. They do not predict the future or copy all live trade risks. This guide is for learning. It is not financial advice or a call to trade.