Portfolio Construction

ETFs as Building Blocks: Portfolio Construction in a Fund of Funds

Why some managers express strategy exclusively through exchange-traded funds — the transparency and liquidity gained, and the trade-offs honestly stated.

Copernicus Investment Manager LLC · Educational article

Most private funds hold individual securities. A smaller number express their entire strategy through exchange-traded funds. The choice has real consequences, in both directions, and it is worth understanding them before deciding whether the approach suits you.

What an ETF-only structure actually means

An exchange-traded fund is itself a pooled vehicle holding many underlying positions. A single broad equity ETF may hold several thousand companies. A manager combining a number of such funds across geographies and asset classes can reach many thousands of underlying positions — without operating a large trading desk to maintain them.

The construction task shifts. Rather than deciding which individual companies to own, the manager decides how much exposure to allocate to each region, sector, asset class, and factor — and when to change those allocations. The work moves from security selection to asset allocation and risk management.

What the approach gains

• Diversification by default. Concentration risk in any single company is structurally limited. Diversification is engineered into the building blocks rather than assembled position by position.
• Daily transparency. Major ETFs publish holdings daily. A manager always knows precisely what the portfolio owns, and so, in principle, can an investor. Compare that with a fund of hedge funds, where underlying managers may report holdings quarterly, with a lag, or not at all.
• Liquidity. Large ETFs trade continuously on exchange in size. A manager wishing to reduce exposure can generally do so the same day — a meaningful contrast with private vehicles carrying lock-ups and redemption gates.
• Low embedded cost. Broad index ETFs commonly charge single-digit to low double-digit basis points. Compare that with the fee layers embedded inside a traditional fund-of-hedge-funds structure.
• Tax characteristics. The ETF creation-and-redemption mechanism tends to generate fewer capital gains distributions than equivalent mutual funds, though outcomes depend on individual circumstances.

What the approach gives up

Any honest description has to include the other side.

• No security-level alpha. A manager who buys the index cannot outperform by picking the best company within it. Whatever edge exists must come from allocation and timing decisions, not stock selection.
• You own the whole index, including its problems. Broad exposure means holding the weak constituents alongside the strong. In a narrow market led by a handful of names, index-level exposure can lag conspicuously.
• A second fee layer exists. The ETF charges its own expense ratio beneath the fund's fee. It is usually small, but it is real and should be counted.
• Correlation clusters in a crisis. Diversification across thousands of securities helps far less when correlations converge toward one, as they periodically do. Broad diversification is protection against idiosyncratic risk, not against systemic risk.
• Tracking and liquidity edge cases. Thinly traded or exotic ETFs can trade away from net asset value, particularly under stress. Instrument selection within the approach still matters a great deal.

What to ask a manager using this approach

1. What determines your allocation changes — discretionary judgment, a rules-based signal, or a combination? How is that documented?
2. What is the total expense load, including the weighted average expense ratio of the underlying ETFs?
3. How do you handle the periods when broad diversification is a disadvantage — narrow, concentrated markets?
4. What liquidity screens do you apply before using a given ETF?

The quality of those answers tells you more about a manager than any single period's returns will.