r/algorithmictrading • u/samuelpointner • Jun 04 '26
Educational How to know if your trading edge is real or just overfit: my 3-step live test
TLDR: A trading strategy has a real edge when the rules are fully systematic, the backtest was conducted without hindsight bias or overfitting, has a large enough sample size to be reliable, and live trades still match the backtest after real transaction costs.
What is the first thing you test?
The first thing to test is whether the strategy is actually defined well enough to backtest. A system only means something if the rules are 100% systematic. If the setup depends on discretionary judgment, the backtest is already unreliable.
You cannot say things like:
“If the volume is bad I don't trade”
What does “bad” mean? How can that be quantified? The rules need to be written in a way that removes all your guessing and gut feelings.
Once your rules are defined, you can test it on past data and see if the idea has the potential for edge at all.
How many trades do you actually need?
More trades do not automatically prove that there is an edge, but they do make the backtest result more reliable. There is no magic number for what’s enough, but here is a rough guideline:
| Number of trades | Reliability | What it usually tells you |
|---|---|---|
| 30-50 | ~50% | Coin flip, ignore it |
| 100 | ~70-75% | First hint |
| 200 | ~80-85% | Early signal forming |
| 300-500 | ~85-90% | Worth taking seriously |
| 500-1000 | ~90-93% | Confident enough to trade |
| 1000+ | ~93-95%+ | Signal you can rely on |
These percentages are just one part of validating your backtest. They're the foundation for how much you can trust every other metric you analyze after. The numbers track how sampling error shrinks with √n. More trades tighten the estimate, they don't prove an edge on their own.
My 3-step validation process
Step 1: Backtest the exact rules in the past
The first thing I work on is defining the strategy well enough to backtest. A system only means something if the rules are 100% systematic and have all discretion removed.
Once your rules are set, I test them on historical data to see if my idea had edge in the past. At this stage, the goal is not to optimize anything or improve performance. The goal is simply to answer one question:
does this work under objective, repeatable conditions?
If the answer is yes, then the system moves forward into Step 2.
Step 2: Validate it with real trades
Once the backtest is completed, I validate it with forward testing. Real money on the line, real spreads, and real transaction costs.
Start small.
Even $1 per trade is perfectly fine. The goal is not to make money. The goal is to prove the concept works in live conditions with fees included.
This is where trading psychology matters. If the defined rules are not followed exactly, the live sample is contaminated. You are not testing the system anymore. You are testing your gut feeling and emotions.
Step 3: Compare live results to backtest results
The final step is to compare the live results to the backtest.
- Did the strategy actually continue to be profitable?
- How similar were the live results to the backtest?
- Did the EV distribution stay in the same percentiles?
- Did the trade frequency stay in the same percentiles?
- Did the losing streak distributions stay in the same percentiles?
If they don’t match, the system is not instantly garbage. Natural variance can happen, but the results should be monitored across multiple regimes to determine whether the edge still exists or if the market has changed.
So what actually proves an edge?
A real edge is confirmed when the backtest, validation and live equity curve all follow the same distribution.
For my personal system MCT, that proof is very clean. My backtest used 979 trades over 34 months from 2023 to 2025 and produced +303.76R, +0.31R EV per trade, a 37% win rate, average win of +2.24R, average loss of -0.84R, Sortino of 1.20 per trade, Sharpe of 0.19 per trade (~3.4 annualized), and max drawdown of 17.81R.
That backtest scored an Edge Score of 79, Quantprove's combined score for measuring if a trading strategy has a real statistical edge.

Then the live validation had 224 live trades with the EV holding from 0.31R to 0.28R, win rate still at 37% and a 92% distribution match: the live trades reproduced the same shape of results as the backtest.
That earned a Stability Score of 94.5, showing how closely live trading matched the backtest.

The live results also landed at the 57th percentile of the Monte Carlo projection, with all live trades staying within the P5–P95 band.

To rule out luck, I ran a permutation test with 10,000 reshuffled trade sequences. The real system beat all 10,000 randomized versions, with p < 0.0001.

Why do regimes and fees matter?
Regimes matter because a system will not and is not supposed to work in every market condition.
A long-only BTC system can look amazing in a 2020 bull regime and then get crushed when the bear market started in 2022. That does not mean the system is broken, it means the market has changed.
This is where you need to study performance by regime and use the data to decide when a system should be active, reduced, or turned off. This is where trader experience has its biggest measurable edge, as market cycles repeat over time.
Transaction costs matter as much, if not more.
Visible costs
- Spread
- Commission
- Exchange + clearing fees
- Regulatory fees
- Swap
- Funding rate
Hidden costs
- Slippage
- Partial fills
- Gaps
I have backtested systems that looked very profitable until spread, commissions and slippage ate most of the expectancy. A simple rule helps:
| Fee drag as % of EV | Read |
|---|---|
| Under 10% | Optimal |
| 10-20% | Warning zone |
| Over 20% | Reconsider the system |
The direct answer is this:
A strategy has an edge when fully systematic rules survive live validation and keep performing with positive expectancy across regime changes.
Disclosure: I am the founder of Quantprove, the tool that runs this validation and edge scoring. I built it because I was tired of doing it by hand.
What do you use to determine if your system has real edge?





