Replaying March 2020: the two weeks that test every rule you have

Most backtests are run on ordinary weeks, because most weeks are ordinary. That is a problem when the thing you want to know is what your rules do under pressure. For that you need a stretch of history where the pressure is real, and the second and third weeks of March 2020 are the clearest example on the chart.

What actually happened

Between Monday 9 March and Friday 20 March 2020, as the pandemic closed economies and everyone scrambled for dollars, the pound fell from around $1.32 to below $1.15 — its lowest against the dollar since 1985. The euro dropped from roughly $1.15 to about $1.07 over the same days. Gold, which is supposed to be the safe place, fell from around $1,700 to roughly $1,450 in the first week as funds sold whatever they could to raise cash. Daily ranges that would normally be a month’s worth arrived every single session.

None of that is a secret, which is exactly the difficulty with replaying it.

Setting it up so the test is honest

You already know the direction. The only way to get anything out of this fortnight is to remove as much of that advantage as the tool allows.

1. Start on Friday 6 March, not Monday 9th. Give yourself two quiet sessions before the move so you are not sitting there waiting for the drop.

2. Use tick-by-tick printing. On a bar-by-bar replay the moves look clean and inevitable. Minute by minute they look like every other reversal, right up until they do not.

3. Set a starting balance you would really trade, and turn on a prop-firm rule set even if you never intend to buy a challenge. A 5% daily loss limit on a week like this is the whole lesson.

4. Write your rules into the session before you press start — the maximum number of trades, the risk per trade, the hour you stop. The discipline score at the end measures you against what you wrote, not against what you wish you had written.

What to watch for in yourself

The trades are not the interesting part. The interesting part is the eleventh minute after a loss. When a range that usually takes a day arrives in an hour, a fixed stop gets hit by noise, and the temptation to re-enter immediately, bigger, is enormous. Tag those trades honestly in the journal — Revenge and FOMO are there for a reason — and the Reports page will tell you what they cost.

The other thing to watch is size. Risk 1% of the account with a stop that fits the volatility and the position is tiny compared with what you are used to. Most people cannot resist making it bigger. That is the test.

Run it more than once

One pass through this fortnight tells you how you reacted once. Run it three times, on different timeframes, and the journal starts to show whether the reaction is a habit. Use the same strategy name each time so the Analytics page groups them together.

Then go and replay a boring week in 2017, and notice how much easier your rules are to keep when nothing is happening. That gap is the thing worth working on.