Take Your Profit Too Soon: The Zurich Axiom That Contradicts Everything

Every trading book you have read contains the same instruction. Cut your losses. Let your winners run.

Max Gunther, writing down what Swiss speculators actually did rather than what they said, disagreed. His axiom is blunt: always take your profit too soon.

Decide the exit in advance, take it when it arrives, and accept that the market will frequently continue without you. The urge to catch the top, he argued, is not skill. It is greed wearing an analyst’s costume, and it is the reason speculators who were right end up flat or worse.

One of these positions is wrong. Most articles resolve this by pretending the disagreement does not exist. We are going to resolve it by computing it, and the answer is a number.

Gunther’s case, simulated

Take a mean-reversion system, the kind that fades an extension back to value. Seven trades in ten reach value, which sits at +0.8R. The trade could be closed there.

Or it could be held. Because sometimes price does not stop at value, it carries on to +1.8R. But sometimes it touches value, turns, and comes all the way back through your entry to a full 1R loss.

Everything depends on how often that second thing happens. Call it the reversal rate.

There is the number. 35.7 percent.

If more than about thirty-six percent of your would-be winners give the whole thing back when you hold them past target, taking the profit early is not a psychological weakness. It is the correct decision, and holding is the mistake.

And note where that leaves the trader who has been told to let winners run. He holds. Half of them reverse. His system, which had a genuine +0.259R edge, now has an expectancy of minus 0.020R. He did the thing every book told him to do and it converted a profitable strategy into an unprofitable one.

Where the axiom becomes suicide

Now run a trend system. Thirty percent win rate. Winners are not bounded: they are drawn from a fat-tailed distribution with an average of 3R, which means most winners are small, a few are enormous, and the enormous ones are the entire business.

Apply Gunther’s advice. Cap the winner.

Read the highlighted row. Capping the winner at the average winner produces a losing system.

That sentence should feel impossible, and it is the single most important thing on this page. In a fat-tailed distribution the mean is not in the middle. The mean is dragged upward by rare, enormous outcomes, so a cap set at the mean removes almost all of the profit while retaining all of the losses.

Gunther’s axiom, applied here, does not reduce this trader’s returns. It destroys them, at every cap level below 5R.

So who is right

Both. Neither is making a claim about discipline, though both are read that way.

They are making claims about the shape of the winner distribution, and they happen to be describing different shapes.

The bottom row is the reason trading advice is so unreliable. Both instructions are true. Each is lethal to the trader running the other system, and neither book tells you which one you are.

Finding out which one you are

You do not need to guess. Two numbers, both computable from your own journal tonight.

1. The reversal rate. Of the trades that reached your target, how many would have come back through your entry if you had held them? You can reconstruct this from the price data. If it is above roughly thirty-six percent, cap the winner and stop apologising for it.

2. The winner distribution. Sort your winners by size in R. Compute what fraction of your total gross profit came from the largest ten percent of them. If that number is small, your tail is thin and Gunther is your author. If it is large, capping will kill you, and the next article in this pair is about exactly how large that number turns out to be.

Two more places the axiom is quietly correct

The funded account. A trailing drawdown limit truncates your own upside for you. Once the firm has capped how much adverse variance you may experience, your effective payoff distribution is thin whatever the market is doing, and taking profit early stops being weakness and becomes compliance with the rules of the game you actually signed.

The range regime. Whatever your instrument, when the market is rotating inside a band the winner is bounded by the band. The trader who lets his winner run to the top of the range and then holds is not letting a winner run. He is donating it to the seller waiting at the edge.

Both are the same observation. The axiom is not about the market. It is about where your upside has been truncated, and by whom.

What Gunther actually understood

He was writing about speculators, not about trend followers, and he never claimed otherwise. The Swiss bankers he described were taking bounded positions in bounded moves, and the failure mode he watched destroy them was not cutting winners early. It was holding for a top that never arrived, and giving back a profit that had been real, and then explaining it as patience.

That failure is real, and it is common, and it kills a particular kind of trader.

It is also the exact opposite of the failure that kills the trend follower, who cuts at 1.2R and never once holds the trade that would have paid for his year.

Read both. Then find out which one you are, because the market will not tell you, and the book you happen to have read first will tell you wrong half the time.