Diversification and geopolitical shock: what the Iran conflict tells us about portfolio construction
Ben Wieland · Apr 13, 2026 · Wealth Management
On 28 February 2026, the United States and Israel launched coordinated airstrikes on Iran. Within hours, the Strait of Hormuz — the narrow waterway through which roughly 20 per cent of the world's daily oil supply flows — was effectively closed. Oil prices surged. Stock futures fell. LNG prices in Asia spiked by over 60 per cent. Global markets, already navigating the turbulence of tariffs and sticky inflation, absorbed another severe shock.
What followed was, for investors, less a geopolitical event than a portfolio test. The portfolios that held up were the ones built before the shock, not after it.
The Strait of Hormuz and your investment portfolio
At first glance, a naval chokepoint in the Persian Gulf might seem a world away from an Australian investor's portfolio — whether it is held inside superannuation, through a family trust, a self-managed fund, or simply as personal investments. Markets do not respect geography.
The International Energy Agency has described the current disruption as the "greatest global energy security challenge in history." Brent crude surged past $120 per barrel — levels not seen since 2022. LNG spot prices in Asia jumped more than 140 per cent after Iranian strikes on Qatar's Ras Laffan complex damaged 17 per cent of Qatar's production capacity. Inflation forecasts have been revised upward across developed economies. The European Central Bank has already postponed planned rate cuts. Economists are now flagging elevated risks of stagflation — low growth combined with high inflation — in energy-intensive economies.
Energy prices reach well beyond petrol at the bowser. They feed into transport costs, food production (through fertiliser), manufacturing, and corporate margins broadly. When energy spikes, the ripple effect reaches almost every sector of the economy — and therefore almost every investment portfolio.
Geopolitical shocks will recur, repeatedly and unpredictably. What matters is how a portfolio is positioned before they arrive.
What David Swensen taught us about uncertainty
The late David Swensen, who managed Yale University's endowment for over three decades and grew it from $1.3 billion in 1985 to roughly $31 billion at his death in 2021, is widely regarded as one of the greatest institutional investors of the modern era. His philosophy was elegant in its simplicity and disciplined in its execution.
Swensen's central insight was that diversification across asset classes with genuinely uncorrelated return drivers — not merely owning many stocks — is what produces resilient long-term returns. Applied to individual investors, the implication is plain: many are over-concentrated in a single asset class, typically domestic equities or residential property, mistaking superficial variety for genuine diversification.
His model endowment allocated meaningfully to domestic equities, international equities, fixed income, real assets (including real estate and commodities), and alternative investments. The logic: when one asset class is stressed, others may hold steady or even benefit. Diversification, on this view, is not about reducing returns. It is about earning returns across the full range of economic conditions.
This matters in 2026 more than it has for some years. Consider how different asset classes have responded to the Iran conflict.
Equities broadly fell on the news, with Asian markets — more exposed to Middle Eastern energy — declining more sharply than US markets. Energy stocks and commodities surged, with oil majors and defence contractors posting significant gains. Gold and other safe-haven assets attracted capital as investors sought stability. Fixed income in certain markets benefited as central bank rate expectations were repriced. Domestic Australian assets, cushioned to a degree by geography and domestic energy production, showed relative resilience compared with more exposed markets.
A portfolio holding only one or two of these would have carried the full force of the shock.
Diversification is owning several sources of return
One of the most common misconceptions we encounter is that diversification means diluting returns by spreading money thinly across many things. Swensen's framework points the other way. Diversification is not about watering down a portfolio. It is about identifying multiple, different return streams that respond differently to economic conditions.
He distinguished three sources of return: asset allocation — the strategic mix of asset classes, which he called the most important decision an investor makes; market timing — moving in and out of markets in response to events, which he considered largely futile; and security selection — picking individual stocks or bonds, which adds complexity without reliably adding returns for most investors.
The implication for today's environment is clear. Investors who attempted to "time" the Iran conflict — getting out of equities before the strikes, rotating into energy just in time — were attempting something no one can do reliably. The strikes came during active peace negotiations, on a day when Oman's foreign minister had announced a "breakthrough." No one predicted the exact moment.
What a well-constructed, diversified portfolio did instead was absorb the shock. Energy and commodity holdings rose. Safe-haven assets provided ballast. International diversification meant the portfolio was not solely exposed to any one region's vulnerability.
This is what asset allocation is designed to do — to be ready for the next crisis, rather than to predict it.
The Australian context: relative insulation, real exposure
Australian investors have some natural advantages in this environment. Australia is a significant energy exporter — particularly LNG — meaning an energy price shock of this magnitude can actually be positive for parts of the domestic economy and equity market. The Australian dollar, often sensitive to commodity prices, has a degree of natural hedge against energy-driven inflation.
This does not mean Australian investors are insulated. Australia is deeply integrated into global trade and capital markets. Australian investors hold wealth across a range of structures — superannuation, self-managed super funds, family trusts, investment bonds, and direct personal portfolios. Many of these, particularly superannuation, are deeply integrated into global markets by design, which is a strength over the long run and also means real exposure to the kinds of global dislocations we are currently experiencing.
Moreover, as a trading nation heavily reliant on Asian demand — and given that Asian economies are among the most severely affected by Middle Eastern energy disruptions — the indirect effects on Australian exports and growth are meaningful.
The lesson is not to retreat into domestic assets. It is to keep international diversification balanced: capturing the upside of global growth while not being over-exposed to any single region's geopolitical risk.
The enduring principle: build the portfolio before the storm
The investors who fare worst in crises are usually those who make their most important portfolio decisions in response to them. Panic selling into a falling market and chasing rising assets after they have already moved are two of the commonest ways long-term wealth is lost.
The discipline David Swensen advocated — and that we apply at EGU — is to construct a portfolio with deliberate, considered asset allocation based on your goals, time horizon, and risk tolerance; and then to rebalance systematically back to that allocation when markets move, rather than reacting emotionally to headlines.
In practical terms, that means a meaningful allocation to real assets, including commodities and infrastructure, which can act as an inflation hedge when energy prices surge; international equity exposure that captures global growth without concentration in any one market; fixed income holdings calibrated to your specific income needs and risk profile; and periodic rebalancing so the portfolio does not drift into unintended concentrations as markets move.
The Iran conflict is an acute reminder that the world is uncertain and always will be. The 1973 oil embargo, the 1979 Iranian Revolution, the Gulf War, September 11, the Global Financial Crisis, COVID-19 — each one looked unprecedented at the time. Each one rattled markets. In each case markets recovered over a long enough horizon, and diversified investors who held their allocation recovered with them.
Ben Wieland
Partner, Wealth Manager
1300 102 542 | 0423 710 820
ben@egu.au
Sources
- Al Jazeera — US and Iran fail to reach a deal after marathon talks in Pakistan (12 April 2026): https://www.aljazeera.com/news/2026/4/12/us-and-iran-fail-to-reach-peace-deal-after-marathon-talks-in-pakistan
- Al Jazeera — Why the oil and gas price shock from the Iran war won't just fade away (23 March 2026): https://www.aljazeera.com/opinions/2026/3/23/why-the-oil-and-gas-price-shock-from-the-iran-war-wont-just-fade-away
- Al Jazeera — How badly has the Iran war hit the global economy? (16 March 2026): https://www.aljazeera.com/news/2026/3/16/the-tell-tale-signs-how-bad-has-the-iran-war-hit-the-global-economy
- World Economic Forum — The global price tag of war in the Middle East (March 2026): https://www.weforum.org/stories/2026/03/the-global-price-tag-of-war-in-the-middle-east/
- TIME — As Peace Talks on Iran Approach, How Soon Could Prices Go Down? (April 2026): https://time.com/article/2026/04/09/oil-gas-commodity-prices-iran-war/
- CNN Business — Oil surges and stock futures sink as war in Iran threatens crude supply (1 March 2026): https://www.cnn.com/2026/03/01/business/oil-prices-us-attack-iran-vis
- Dallas Fed — The Impact of the 2026 Iran War on U.S. Inflation, Kilian, Plante, Richter & Zhou: https://www.dallasfed.org/~/media/documents/research/papers/2026/wp2609.pdf
- David F. Swensen — Pioneering Portfolio Management: An Unconventional Approach to Institutional Investment (Free Press, 2000; revised 2009)
This is general advice. It does not take account of your objectives, financial situation, or needs, and is not a substitute for advice that does. Before acting on anything in it, consider whether it suits your circumstances, and consider the relevant Product Disclosure Statement.