The cost of convexity

Most investors think about protection emotionally.

They want the portfolio to feel safer. They want drawdowns to hurt less. They want some part of the portfolio to respond when the world becomes unstable. This instinct is understandable. But in investing, the instinct to reduce pain can itself become expensive.

A hedge is not useful simply because it performs during a crisis. A risk strategy is not valuable merely because it lowers volatility. The real question is harder: does it improve the long-term compounding of the portfolio as a whole?

Convexity, as used here, refers to positions whose potential payoff is asymmetrically large relative to their ongoing cost — instruments that may lose a small amount across ordinary conditions but respond disproportionately when markets become dislocated or nonlinear.

Spitznagel's central point is uncomfortable: risk mitigation can easily become the costliest thing an investor does. The cure can become worse than the disease. A strategy that feels prudent in isolation may quietly reduce the very compounding it was meant to protect.

At Aeternia, convexity is judged by this standard.

The false comfort of protection

There are many ways to make a portfolio look safer.

An investor can hold more cash. Buy broad hedges. Diversify endlessly. Reduce exposure. Avoid concentration. Own assets that appear defensive. Each of these may reduce one form of risk, but each also carries a cost.

The cost may be explicit, as with option premiums. It may be implicit, as with holding too much cash during long periods of market strength. It may be behavioral, as with a portfolio so diversified that the best ideas no longer matter. It may be intellectual, as with risk models that make the portfolio appear safer while missing the deeper source of fragility.

The common mistake is to evaluate protection in isolation.

A hedge that pays off during a crash looks successful on its own statement. But if it has drained returns for years before that moment, the portfolio may still be worse off. The question is not whether the hedge worked. The question is whether the total journey was improved.

The measure is not drama. The measure is compounding.

Convexity and the roundabout path

Spitznagel's idea of roundabout investing, drawn from Austrian economics, offers a useful frame.

The Austrian tradition emphasizes the importance of time, capital structure, and indirect production. The most productive path is often not the most direct path. Capital must sometimes move through a more circuitous route in order to produce a greater result later. The roundabout path often looks inefficient in the short term — it requires patience, foregoing immediate gratification, and it may involve small, visible losses in order to create larger, less visible future advantages.

Convexity can be understood in this way.

A well-designed convex position may appear to lose money most of the time. It may look wasteful during calm markets. But if its cost is controlled and its payoff is sufficiently asymmetric, it can create a future advantage that could not have been purchased after the fact.

This is the key distinction. Roundabout investing is not the same as casually accepting drag. The indirect path must still be productive — it must create a future benefit greater than its interim cost. Otherwise, it is not roundabout. It is simply waste.

Preservation and home runs

Stanley Druckenmiller has often framed long-term investment success around two ideas: preserve capital and pursue home runs when the opportunity is unusually favorable.

This is not a call for constant aggression. It is almost the opposite.

It requires the patience to wait, the discipline to avoid ruin, and the courage to act decisively when the odds are sufficiently attractive. The great opportunities are not evenly distributed through time. They appear irregularly, often when other investors are constrained, frightened, overleveraged, or forced to sell.

The ability to act in those moments is itself an asset. But that ability must be preserved in advance. It cannot be manufactured after the dislocation has already arrived.

This is one of the underappreciated purposes of convexity. It is not merely about cushioning losses. It is about preserving the freedom to move when opportunity becomes abundant.

Cash alone can provide some of that flexibility, but it carries its own opportunity cost across long stretches of market strength. Broad diversification reduces some volatility but dilutes conviction. Convexity, when cost-controlled and properly sized, offers a different path: a small part of the portfolio that may become more valuable precisely when the rest of the market is becoming more constrained.

That is why cost matters so much. If the convexity allocation is too expensive, it weakens the core. If it is too small or poorly structured, it fails to matter when needed. If it is too broad or constant, it becomes a tax. If it is too speculative, it becomes entertainment.

The discipline lies in making convexity useful without allowing it to dominate.

The Aeternia structure

Aeternia begins with compounders.

The core of the portfolio is intended to own exceptional businesses: companies with durable advantages, strong or improving returns on capital, disciplined management, and the ability to reinvest over long periods of time. These businesses are the primary engine.

Convexity sits at the edge. It is not the identity of the portfolio. It is not a substitute for owning great businesses. It is not a permanent bet on collapse. Its role is more selective: to preserve resilience, create asymmetry, and maintain the ability to act during dislocation.

This distinction is essential. A portfolio built entirely around hedging may spend too much time waiting for disorder. A portfolio built entirely around compounding may underestimate how disorder interrupts compounding. Aeternia seeks the synthesis: own what compounds, while preserving the ability to remain invested and act when the world becomes mispriced.

What useful convexity must satisfy

Not every hedge is useful. Not every option is convex in a way that matters. Not every asymmetric payoff improves the portfolio.

The first condition is cost. The portfolio cannot afford to pay so much for protection that ordinary compounding is impaired — this is the test that eliminates most conventional hedging strategies. The second is magnitude: a small position is only useful if it has the potential to matter during the kinds of environments in which the portfolio needs help. A hedge that pays out modestly when the world breaks badly is not convexity. It is noise.

Beyond cost and magnitude, the position must improve the behavior of the whole portfolio, not just look attractive in isolation. Many strategies that appear well-constructed in a vacuum add little when placed alongside a concentrated equity book. And critically, useful convexity must increase the ability to act — not merely reduce pain. The best convex positions do something rarer: they create future optionality precisely when optionality is most valuable.

These conditions are demanding. They are intended to be. Convexity should be selective — the goal is not constant insurance against every imagined risk, but to identify situations where the price of asymmetry is genuinely attractive relative to its potential contribution to the whole. If it is too speculative, it becomes entertainment. If it is merely cautious, it becomes a tax.

The objective

Investors often confuse smoothness with safety.

A smooth portfolio can still be fragile. A volatile portfolio can still be durable. What matters is not the absence of movement, but the absence of permanent impairment and the preservation of long-term earning power.

The objective is not the smoothest path. It is the highest durable rate of compounding. That requires accepting some ordinary volatility, owning assets capable of creating value through time, and avoiding strategies that offer psychological comfort at excessive economic cost. And it requires maintaining enough resilience to survive environments in which opportunity and danger arrive together.

Protection is not the goal.
Compounding is the goal.
And the right kind of protection exists to keep compounding alive.