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Position sizing
How much you own of something matters more than whether you were right about it.
Two investors can hold identical portfolios of the same ten companies and end the decade with completely different outcomes, because they held them in different proportions.
The asymmetry that does the damage
Wealth Signal calculation
A 50% loss requires a 100% gain to recover
Fall from 100 to 50 and you need to double from there to get back. Fall to 20 and you need to quintuple. This is arithmetic, not opinion, and it is why avoiding large losses matters more than capturing large gains.
Fall from 100 to 50 and you need to double from there to get back. Fall to 20 and you need to quintuple. This is arithmetic, not opinion, and it is why avoiding large losses matters more than capturing large gains.
A position small enough that its total failure would be survivable behaves completely differently in your mind from one that is not. The same company, the same thesis, a different size — and a different set of decisions under stress.
The practical question
Not “how confident am I?” but “what happens to the whole if this one goes to zero?” Confidence is a feeling that correlates poorly with being right. The second question has an arithmetic answer.
Why concentration is both routes
- Concentration builds most large fortunes. Almost nobody becomes wealthy through a widely diversified portfolio of modest positions.
- Concentration destroys most large fortunes too. The same mechanism, run in the other direction.
- The survivors are the ones you hear about, which makes concentration look better than the full record supports.
Interpretation
Size the position to the consequence, not to the conviction
You cannot control whether you are right. You can control what being wrong costs you. Only one of those two is a decision you actually get to make.
You cannot control whether you are right. You can control what being wrong costs you. Only one of those two is a decision you actually get to make.
A holding that has grown into a very large share of a portfolio was not sized that way — it got there by succeeding. It is still worth asking whether you would choose that size today.
Education, not advice. These lessons explain how things work. They do not tell you what
to buy, and Wealth Signal does not publish recommendations. Full disclaimer.