The High-Water Mark

A high-water mark is the line a fund has to clear before it earns anything on new gains. Below the line, the work is uncompensated. The name is a reminder that the only performance that counts is performance measured from the last peak, not from a convenient low.

That framing shapes how I think about holding things. Most portfolios are wide because width feels safe. It rarely is. Width dilutes your best ideas down to the level of your average one, and your average idea is usually not worth owning. Concentration is uncomfortable precisely because it removes the place to hide.

What concentration actually requires

Holding few things forces three commitments most investors avoid:

• A thesis you can write down. If you cannot state, in a paragraph, what has to be true for the position to work and what would prove you wrong, you do not own a thesis. You own a feeling.
• A reason the price is wrong. A good business at a fair price is not an opportunity. The edge is in the gap between what the crowd has priced and what you can defend.
• The patience to be early and wrong-looking. Conviction that evaporates on a drawdown was never conviction.

Oversold is a feeling until you anchor it to a thesis.

Invalidation, not stops

Mechanical price stops sell you out of your best ideas at the worst moments. The alternative is harder and better: define, in advance, the specific facts that would break the thesis. A missed quarter is noise. A permanent change in the competitive position is a trigger. The job is to tell them apart under pressure, which is why you write it down before you are under pressure.

None of this is a formula. It is a set of habits that make it possible to hold a small number of things through the periods that shake everyone else out. That is the whole game.