I copied a trading study exactly and found a 36% drawdown

A study looks safe until you test it on your own rules. Copying the study exactly would mean a hypothetical loss of about 36,000 dollars on a 100,000 dollar account, compare it with your own loss limit.

An Instagram reel asks if an exact copy works in your account. The question in your words is, Is it true that a strategy that reproduces a study exactly will work in your account? I answer it with one exact test on index markets at a broker, and I show you how to read your own report in five minutes.

Why an exact copy feels safe

A clean paper is tempting. Every rule is written down, so you think there's no room left for doubt. A strategy that reproduces a study exactly will work in your account. That's the hope, and it's easy to see why it sticks.

You pay for a challenge and you need clear rules, not guesswork. A paper looks clear for a minute. But a paper is not your account. Your account has a loss limit that can end your challenge.

That's why I don't start with trust. I start with the worst fall in dollars.

What the test did

We reproduced an earnings-season effect from a study exactly, then traded it on nine index markets at a broker: -2.9% a year and a 36% drawdown. The test covered February 2017 through 2021 and kept every rule as written.

I kept it exact on purpose. I didn't add my own ideas and I didn't change a rule to fit the years. The point was to see if an exact copy holds up outside the paper.

These are index markets at a broker. You trade the broker price that follows the index. That's the market this test used.

What minus 2.9% a year and a 36% fall mean

Minus 2.9% a year means the value went down a little each year on average. It's a yearly rate, not one single year. A small yearly number can still hide a much larger fall along the way.

A 36% drawdown means the value fell 36% from a past peak to the next low. Drawdown is that peak to trough fall. It's the number that ends challenges, because your firm watches your current value, not your yearly average.

On a 100,000 dollar starting size, a 36% fall at the same scale is a hypothetical loss of about 36,000 dollars from peak to trough. That's not a real challenge result. It's what the same percentage fall would look like in dollars on that size.

Now place that dollar fall next to your own loss limit from your written rules. If your limit is smaller than that fall, the same rules would have stopped you. You don't need to guess what other firms allow. You only need your number.

Your own costs are a separate check. Spreads and fees differ by broker and they change your own result. Check them in your own report, apart from this test.

What I do

I compare that 36% fall with your own loss limit before I trust an exact study copy. The paper result is exact, but the fall in dollars decides if the rules fit your limit. That pair matters more to me than the yearly average.

Your five minute check

Open your report, find the largest fall in dollars and compare it with your challenge loss limit. That's the whole check, and you'll be done in five minutes.

Open the report you already have from your own test. Find the largest peak to trough fall in dollars. Write down your own challenge loss limit in dollars from your written rules. Put the two dollar numbers side by side.

If the fall is larger than your limit, the same rules would have stopped you. If it's smaller, you still need to check your costs and your prices apart. Don't mix those checks. First the fall, then your own costs.

Try the free Prop Rule Guard before you pay your next fee.

This was a historical simulation, not a live account.