The US-Iran War: Portfolio Risks, Market Signals, and the Road Ahead


The weekend of 28 February 2026 marked a decisive shift in global geopolitics, with immediate and far-reaching implications for financial markets. The United States, alongside Israel, launched coordinated military operations inside Iran, targeting key military leadership and nuclear infrastructure. Among the reported outcomes was the death of Supreme Leader Ayatollah Ali Khamenei. Iran responded swiftly with retaliatory missile strikes across the region, targeting US military bases and critical infrastructure, including Gulf state airports such as Dubai International, while emergency sessions were convened at the United Nations.

This escalation, long anticipated following the collapse of diplomatic negotiations in late 2025, has now materialised into a direct and sustained military confrontation. What had previously been characterised by proxy engagements and strategic posturing has transitioned into a full-scale conflict between the United States and Iran. This represents an event without modern precedent in its current form.

Markets reacted immediately. Oil prices surged as supply risks were repriced, gold moved to record highs amid a flight to safety, and risk assets sold off as investors reassessed the global risk premium.

For investors, the question is no longer whether geopolitics matters for portfolios—it clearly does. The more important considerations are how deep the impact will be, how long it may persist, and through which channels it will ultimately influence asset prices.

Understanding the Macro Context

Before assessing market implications, it is important to ground the situation within its broader context.

The recent strikes did not occur without warning. Tensions have been building since mid-2025, when Israel targeted Iranian nuclear facilities in a 12-day conflict that also involved limited US participation. Diplomatic efforts continued in the months that followed, with talks mediated by Oman and held in Geneva extending into late February 2026. However, these negotiations ultimately collapsed without resolution just days before the strikes commenced.

At the same time, the United States had been increasing its military presence in the region, with a buildup widely regarded as the largest since the 2003 Iraq invasion. This deployment signalled a clear shift in posture, and markets had already begun to incorporate a degree of geopolitical risk into asset prices.

A further catalyst emerged domestically within Iran. Nationwide anti-government protests intensified in late December 2025, driven by a deepening economic crisis, sharp currency depreciation, and rising cost-of-living pressures. The government’s forceful response added another layer of instability to an already fragile environment.

The United States has cited both the internal crackdown and Iran’s alleged nuclear ambitions as justification for its actions. Regardless of the framing, the outcome is evident. The situation has moved beyond diplomatic tension into open and sustained conflict, with significant implications for global markets.

The Strait of Hormuz: The Variable That Matters Most

For global markets, the defining question is not who prevails in this conflict, but whether the Strait of Hormuz remains open. Approximately 13 million barrels of crude oil pass through the strait each day, accounting for around 30% of global seaborne oil flows and roughly 20% of total global consumption. As the world’s most critical energy chokepoint, any disruption would translate directly into higher oil prices and broader macroeconomic pressure. This is the primary channel through which geopolitical risk becomes market risk.

Two scenarios frame the current outlook. In a contained conflict, military actions remain targeted and time-bound, with shipping flows largely uninterrupted. Oil prices may spike as a risk premium is priced in, but stabilise as supply continuity becomes clear, consistent with the pattern observed in June 2025. In contrast, a prolonged escalation would involve sustained attempts to disrupt traffic through the strait, whether via naval activity, mining, or continued strikes on regional infrastructure. Even partial interference would tighten supply conditions, push oil prices higher, and reinforce inflationary pressures.

At present, markets are not pricing a full closure of the strait, but they are assigning a growing premium to disruption risk. The distinction is important. The key risk lies not only in the severity of disruption, but in how long that risk persists.

What Markets Are Doing Right Now

With markets open on Monday, investors are navigating a broad risk-off shift across asset classes. Early price action reflects a rapid repricing of geopolitical risk, with a pronounced divergence between defensive assets and growth-sensitive sectors.

Oil and Energy 
Energy markets have moved first. Brent crude settled at US$72.48 on Friday, already up approximately 19% year to date, while WTI closed at US$67.02. In the immediate aftermath of the weekend strikes, oil futures rose by around 5%, reflecting the rapid incorporation of supply risk. Energy equities had already been outperforming in the lead-up to the escalation, with ExxonMobil (XOM) and Chevron (CVX) both gaining more than 11% year to date. The sector has seen sustained rotation in recent weeks, suggesting that part of the geopolitical premium may already be priced in. This introduces a more nuanced risk-reward dynamic for investors considering incremental exposure.

Defence
Defence stocks are emerging as the clearest near-term beneficiaries. Lockheed Martin (LMT) and Northrop Grumman (NOC) had risen approximately 14.9% and 10.9% respectively year to date prior to the weekend, reflecting elevated geopolitical tensions. Boeing (BA) and Elbit Systems (ESLT) are also seeing positive early sentiment. These moves are underpinned by expectations of increased defence spending, a theme that is likely to remain supported should the conflict persist.

Gold
Gold continues to perform its traditional role as a safe-haven asset. Futures rose approximately 1.2% following the strikes, with spot prices trading near US$5,247 per troy ounce as of Monday morning. The metal has already experienced a strong upward trend through 2025 and early 2026. The key question for investors is whether current momentum represents a continuation of structural demand or a more crowded positioning dynamic.

Equities
Global equity markets entered the week from a position of relative fragility. The S&P 500 closed Friday at 6,878, down 0.43%, while the Dow Jones fell 1.05% and the Nasdaq declined 0.92%. Markets had already been contending with geopolitical uncertainty alongside concerns around earnings sustainability, particularly within technology sectors exposed to AI-driven disruption. The VIX rose to 19.86, up 6.60% on the day, signalling a clear increase in risk aversion. Early positioning suggests that high-beta, cyclical, and growth-oriented sectors are likely to remain under pressure. Some institutional commentary has already cautioned against aggressive dip-buying, noting that the current risk-reward profile remains uncertain.

Airlines and Consumer Discretionary
Airlines are among the most impacted sectors. United Airlines (UAL), Delta Air Lines (DAL), and American Airlines (AAL) have all declined sharply, with the US Global Jets ETF (JETS) also trading lower. Rising fuel costs and potential airspace disruptions are weighing on earnings expectations, with similar pressure across consumer-facing sectors.

Currencies and Crypto
Currency markets are reflecting a defensive shift. The US Dollar (DXY) and Japanese Yen (JPY) have strengthened as capital rotates toward perceived safe havens. Higher-risk assets have weakened, with Bitcoin declining approximately 3% over the weekend. The Iranian Rial  has depreciated sharply, reflecting both economic stress and capital flight. 

Bonds
Fixed income markets are seeing renewed demand. US Treasuries (UST) had already been attracting inflows in the lead-up to the escalation, and this trend is expected to continue. Flight-to-safety dynamics are likely to place downward pressure on yields as bond prices rise, although the inflationary implications of higher energy prices may introduce offsetting forces over time.

The ASX: A Split Market

For Australian investors, the market response is more nuanced than the broader global risk-off move. The S&P/ASX 200 fell 0.48% at Monday's open, although sector divergence has been pronounced. Energy names have rallied strongly, with Woodside Energy (WDS) up 6.7%, Santos (STO) up 7.2%, and Beach Energy (BPT) leading with a 10.5% gain, as higher oil and LNG prices are priced in. Gold producers, including Evolution Mining (EVN) and Northern Star Resources (NST), are also benefiting from safe-haven flows, while a weaker Australian dollar, down more than 0.5% in early Asian trade, is providing a partial offset for investors with unhedged offshore exposure.

By contrast, iron ore majors BHP Group (BHP), Fortescue (FMG), and Rio Tinto (RIO) are under pressure, reflecting concerns around global growth and Chinese demand rather than direct exposure to the conflict. China sits at the intersection of two key pressure points, as both the world's largest iron ore importer and a major buyer of Iranian oil. The result is a fragmented market in which energy and gold outperform while cyclicals lag, reinforcing the case for selective positioning rather than broad defensive allocation.

The Duration Problem

One of the most consistent lessons from past geopolitical shocks is that duration is the critical variable. Markets have historically absorbed short and contained conflicts relatively well. The June 2025 Israel–Iran exchange is a recent example, where equities sold off sharply at the open but recovered once it became clear that the Strait of Hormuz remained undisrupted. Both global and Israeli equities ultimately moved higher over the course of that 12-day conflict.

The current situation differs in both scale and stated intent. Operation Epic Fury has been framed by the US administration as extending beyond a limited strike, with objectives that include broader strategic outcomes within Iran. Even with the reported removal of senior leadership, succession dynamics remain uncertain. US intelligence assessments suggest that potential successors are likely to come from hardline elements within the Islamic Revolutionary Guard Corps, which continue to oversee key military, nuclear, and regional proxy networks.

Achieving the stated objectives of dismantling Iran’s nuclear capabilities, degrading its military infrastructure, and influencing political leadership outcomes represents a materially more complex undertaking than prior engagements in the region.

For markets, this reinforces the importance of time horizon. The longer the conflict persists, the greater the probability of conditions associated with prolonged escalation. This includes sustained elevation in oil prices, persistent inflationary pressure, and an extended period of uncertainty that weighs on equity valuations and tightens financial conditions.

Portfolio Implications

This is not an environment that rewards aggressive or highly directional positioning. The next several weeks will be critical in determining whether this remains a short-term volatility event or evolves into a more structural repricing of risk.

Key considerations for investors include:
  • Expect volatility, but not necessarily escalation. Geopolitical shocks often produce sharp market reactions, but not all result in lasting damage. Absent a material disruption to the Strait of Hormuz, historical patterns suggest markets can absorb these events over the medium term. Prior analysis indicates such conflicts are typically too contained to materially alter the global earnings outlook, provided escalation remains limited.
  • Be selective with safe-haven exposure. Gold, US Treasuries, the Swiss franc, and the Japanese yen remain traditional defensive assets. However, positioning had already been building ahead of the escalation. Entering after the initial move risks paying for protection that is already partially priced.
  • Treat energy exposure as a tactical position. Energy assets benefit from rising oil prices but represent a directional trade rather than a pure hedge. Any signal of de-escalation or confirmation that shipping routes remain secure could see the geopolitical premium unwind quickly. Position sizing should reflect this asymmetry.
  • Monitor inflation implications closely. Sustained elevation in oil prices would reinforce inflationary pressures and may alter the expected path of monetary policy. Duration-sensitive assets could face renewed headwinds, while companies with strong pricing power and lower input cost exposure are likely to be more resilient.
  • Maintain discipline in long-term allocations. Historical market behaviour shows that periods of geopolitical stress are often followed by recovery. Investors who exit diversified, long-term positions during peak uncertainty risk missing that rebound. Unless exposure to directly impacted sectors is significant or investment horizons are short, disciplined positioning remains the more effective approach.

Navigating an Uncertain Environment

The current situation is without clear precedent in modern Middle Eastern geopolitics. The reported death of a sitting Supreme Leader in a US-led strike, the breakdown of diplomatic negotiations immediately prior to military action, and the scale of retaliatory activity across the region represent a combination of events that do not align neatly with historical frameworks.

Uncertainty remains high, and no participant can confidently define the path forward. What can be assessed is how markets are likely to respond. Pricing will adjust as new information emerges, with the Strait of Hormuz remaining the key link between geopolitical developments and economic outcomes.

In this environment, disciplined decision-making remains essential. Maintaining diversification, aligning positions with investment horizons, and avoiding reactive adjustments are likely to prove more effective than responding to short-term headlines.

Subscribe to our newsletter

Disclaimer: This article does not constitute financial advice nor a recommendation to invest in the securities listed. The information presented is intended to be of a factual nature only. Past performance is not a reliable indicator of future performance. As always, do your own research and consider seeking financial, legal and taxation advice before investing.

Is a Share Advisor

right for you?

February 27, 2026
Discover how high beta stocks can offer tactical opportunities or pose structural risks in today’s evolving market.
February 26, 2026
Oil prices ease as U.S.–Iran nuclear talks resume, raising hopes of supply relief while investors brace for volatility and shifting inflation outlooks.
February 25, 2026
The Supreme Court ruled, Trump responded in hours. Here's what the new 15% tariff regime means for markets, the ASX, and your portfolio.
February 20, 2026
About Ferrari NV Ferrari N.V., through its subsidiaries, engages in design, engineering, production, and sale of luxury performance sports cars worldwide. The company offers sports, track, one-off, and road cars, as well as supercars. It also provides spare parts and engines, as well as after sales, repair, maintenance, and restoration services for cars; and licenses its Ferrari brand to various producers and retailers of luxury and lifestyle goods. In addition, the company operates Ferrari museums in Modena and Maranello; Il Cavallino restaurant in Maranello; and theme parks in Abu Dhabi and Spain. Further, it provides direct or indirect finance and leasing services; range of financial and ancillary services; special financing arrangements; and operates franchised and owned Ferrari stores. The company was founded in 1947 and is headquartered in Maranello, Italy. Source:EODHD Key Stats
February 20, 2026
In volatile markets, discipline matters most. Learn how dollar-cost averaging supports systematic capital deployment and reduces timing risk.
February 20, 2026
About Amazon.com Inc Amazon.com, Inc. engages in the retail sale of consumer products, advertising, and subscriptions service through online and physical stores in North America and internationally. The company operates through three segments: North America, International, and Amazon Web Services (AWS). It also manufactures and sells electronic devices, including Kindle, fire tablets, fire TVs, echo, ring, blink, and eero; and develops and produces media content. In addition, the company offers programs that enable sellers to sell their products in its stores; and programs that allow authors, independent publishers, musicians, filmmakers, Twitch streamers, skill and app developers, and others to publish and sell content. Further, it provides compute, storage, Artificial intelligence, database, analytics, machine learning, and other services, as well as advertising services through programs, such as sponsored ads, display, and video advertising. Additionally, the company offers Amazon Prime, a membership program. The company's products offered through its stores include merchandise and content purchased for resale and products offered by third-party sellers. It serves consumers, sellers, developers, enterprises, content creators, advertisers, and employees. The company was incorporated in 1994 and is headquartered in Seattle, Washington. Source:EODHD Key Stats
February 19, 2026
Understand how defensive investing can manage risk, generate stable income, and help you pursue consistent, long-term growth in uncertain markets.
February 18, 2026
Assess how Australia’s higher-for-longer rate environment impacts markets, assets, and portfolios, with insights on navigating risks and opportunities.
February 17, 2026
About Alphabet Inc Alphabet Inc. offers various products and platforms in the United States, Europe, the Middle East, Africa, the Asia-Pacific, Canada, and Latin America. It operates through Google Services, Google Cloud, and Other Bets segments. The Google Services segment provides products and services, including ads, Android, Chrome, devices, Gmail, Google Drive, Google Maps, Google Photos, Google Play, Search, and YouTube. It is also involved in the sale of apps and in-app purchases and digital content in Google Play and YouTube; and devices, as well as the provision of YouTube consumer subscription services, such as YouTube TV, YouTube Music and Premium, NFL Sunday Ticket, and Google One. The Google Cloud segment offers consumption-based fees and subscriptions for AI solutions, including AI infrastructure, Vertex AI platform, and Gemini enterprise. It also provides cybersecurity, and data and analytics services; Google Workspace that include cloud-based communication and collaboration tools for enterprises, such as Calendar, Gmail, Docs, Drive, and Meet; and other enterprise services. The Other Bets segment sells transportation and internet services. Alphabet Inc. was incorporated in 1998 and is headquartered in Mountain View, California. Source: EODHD Key Stats
February 17, 2026
Borrowing capital to invest remains the most effective tool available to sophisticated investors seeking to accelerate portfolio growth, yet it is often misunderstood as a "high-stakes gamble." Leverage amplifies your purchasing power, transforming a standard portfolio into a dynamic engine for wealth creation. While the concept of "risk-free" leverage is a mathematical impossibility, the ability to manage risk with institutional-grade precision is entirely achievable. Smart investors do not fear debt because they understand how to structure it as a calculated business strategy rather than a speculative bet. They respect the mechanics of gearing and employ professional oversight to mitigate the downside while capturing the upside of global markets. In 2026, the question isn't just about whether you should use leverage, but how you manage the journey from research to results. By moving away from "set-and-forget" retail habits and adopting an evidence-based framework, you can replace the anxiety of the unknown with the confidence of a professional strategy. How does margin lending work? Margin lending is a strategic tool that allows you to borrow capital to invest in approved shares, using your existing portfolio or cash as security. This creates a Loan-to-Value Ratio (LVR), which dictates your borrowing capacity against specific assets. While the lender holds security over the portfolio, the investor retains beneficial ownership and receives all dividends and franking credits. The mathematics of leverage are compelling when executed with professional-grade research and risk management. Consider a share-specific example: Initial Equity : You start with $100,000 in cash or existing blue-chip shares. The Leverage : You borrow an additional $100,000 to increase your total market exposure to $200,000. The Outcome : If the market rises by 10%, your total portfolio is now worth $220,000. The Professional Result : Instead of a $10,000 gain on your initial cash, you have achieved a $20,000 gain, representing a 20% return on your initial equity (before interest costs). When your portfolio value increases, the gains on the larger asset base belong entirely to you. Furthermore, for high-income earners, the interest on the loan is generally tax-deductible, making the effective cost of borrowing highly attractive. Why do investors fear the margin call? For many investors, the term "margin call" triggers a visceral reaction, often rooted in the "psychological scars" of past share market volatility, where unmanaged debt led to significant capital impairment. A margin call occurs when the market value of your shares falls below the lender's required LVR, forcing you to either contribute immediate cash or sell assets at depressed prices to restore the balance. This mechanism protects the lender but can devastate an unmanaged, "set-and-forget" portfolio. This fear typically stems from a lack of active, professional portfolio management. When you rely on a passive strategy while holding debt, you surrender control to market forces exactly when you need discipline and data-led execution the most. The Sharewise approach to mitigating risk: Proactive market monitoring : Our Chief Investment Officer looks at 5,000 stocks across all markets every day, ensuring we identify shifts before they become critical threats to your LVR. Data-driven discipline : We utilise technical and fundamental analysis to remove emotional "hope" from the equation, implementing strict protocols to protect your capital. Constant communication : Every investor has a dedicated advisor providing one-on-one communication, ensuring you are never left guessing during market corrections. Absolute transparency : Through our managed account structure, you can log in 24/7 to see exactly how your portfolio and leverage are performing, maintaining control with confidence. What is margin lending vs margin loan? Choosing the right debt structure for growth means moving beyond a basic comparison of loan types to understanding exactly how your facility is managed. While these terms are often used interchangeably in financial headlines, there is a strategic difference that every professional investor should recognise. Margin lending refers to the broader program or strategy of borrowing against securities to amplify your investment capacity. In contrast, a margin loan is the specific debt instrument or credit facility you use to execute that strategy. Understanding this distinction is vital for managing your LVR and maintaining absolute control over your financial future. Margin Lending (The Strategy): This is the overarching framework of borrowing to invest, technically known as "gearing". It requires institutional-grade research and constant vigilance to ensure your leverage supports growth without creating unmanaged risk. Margin Loan (The Product): This is the actual line of credit that carries the interest rate. When you are searching for the best margin lending rates, you are effectively comparing the cost of different margin loan facilities against the potential performance of your shares. By focusing on the margin lending strategy as a whole, rather than just the margin loan balance, you ensure your borrowing is supported by proactive market monitoring rather than just passive debt. Why margin lending outperforms generic debt When seeking to accelerate wealth, the choice of borrowing is just as critical as the choice of shares themselves. While many investors consider standard debt products, margin lending is specifically engineered for the equity market, offering a level of institutional-grade precision that generic borrowing cannot match. Choosing margin lending over other vessels of borrowing is a strategic decision for the serious investor. While personal loans or bank overdrafts can technically be used to buy shares, they are "blunt instruments" not designed for market dynamics. Risk Mitigation: Personal loans and overdrafts have no built-in LVR monitoring. Margin lending, when paired with professional portfolio management, includes daily oversight to ensure market dips don't become financial disasters. Tax Efficiency: In Australia, interest on a margin loan used to acquire income-producing shares is generally tax-deductible. While other loans can be deductible if used solely for investing, the administrative burden of "tracing" those funds is complex compared to a purpose-built margin lending facility. Cost of Capital: Because margin lending is secured against a liquid share portfolio, lenders often provide the best margin lending rates, whereas personal loans are unsecured and carry significantly higher interest costs that can eat into your investment performance. Cash Flow & Liquidity: An overdraft often requires rigid repayment schedules. Margin lending offers the flexibility to pay interest from dividends or capitalise it into the loan, allowing your share portfolio to compound more efficiently. Securing the best margin lending rates is only the first step; the real value lies in the active management of those funds. By moving away from "passive debt" and embracing a managed account structure, you transform a simple loan into a sophisticated utility for market outperformance. The path to risk-aware leverage While no investment is devoid of risk, the fundamental difference between reckless gambling and strategic gearing lies in the professional management framework. Securing the best margin lending rates is only the first step; the real value lies in the active management of those funds to ensure your share portfolio consistently outperforms the cost of debt. Professional advisors and investment managers utilise managed accounts to monitor LVR levels daily. This vigilance ensures that minor market dips are addressed before they become critical margin calls, providing professional portfolio management without losing control. The historical data supports a strategic approach; while Australian shares have delivered strong long-term averages, the real "profit margin" for the investor is the spread between the cost of debt and the potential return. Because interest on investment loans is generally tax-deductible for Australian residents, the real cost of holding a leveraged position is significantly lower than the headline rate. Risk aware leverage involves three core pillars: Conservative LVRs: Never borrowing to the maximum limit allows a buffer for market volatility. Diversification : Spreading capital across unconnected sectors reduces the likelihood of the entire portfolio dropping simultaneously. Active Management: Using a professional service to rebalance the portfolio proactively rather than reactively. To truly understand how professional management protects your capital, compare the Sharewise institutional approach against the typical retail experience: