Oil - why the black stuff still matters so much in geopolitics, markets and portfolios
6th March 2026
Oil has a habit of moving from the business pages to the front pages very quickly.
Most people know that higher oil prices can mean more expensive petrol, pricier flights and renewed inflation worries. What is less well understood is why oil still sits so close to the centre of geopolitics, despite all the talk of electrification, renewable energy and the energy transition.
The short answer is that oil remains deeply embedded in the global economy. It fuels transport, aviation, shipping, logistics and defence. It is also a critical input in plastics, chemicals and industrial production. Because it is both economically essential and geographically concentrated, oil becomes something more than just another commodity. It becomes a strategic resource.
That is why oil frequently sits at the intersection of geopolitics, economics and financial markets.
Most people know that higher oil prices can mean more expensive petrol, pricier flights and renewed inflation worries. What is less well understood is why oil still sits so close to the centre of geopolitics, despite all the talk of electrification, renewable energy and the energy transition.
The short answer is that oil remains deeply embedded in the global economy. It fuels transport, aviation, shipping, logistics and defence. It is also a critical input in plastics, chemicals and industrial production. Because it is both economically essential and geographically concentrated, oil becomes something more than just another commodity. It becomes a strategic resource.
That is why oil frequently sits at the intersection of geopolitics, economics and financial markets.
Why oil is still a geopolitical lever
One of the main reasons oil matters geopolitically is geography. Large volumes of global supply must move through a small number of chokepoints. The most important of these is the Strait of Hormuz, which sits between Iran and the Gulf states.
In normal conditions, roughly a fifth of the world’s oil supply passes through this narrow shipping route. That means disruption there can very quickly become a global economic issue rather than just a regional one. It is one of the clearest examples of how a physical bottleneck can turn energy supply into a geopolitical pressure point.
Recent events have illustrated this vividly. Iran’s closure of the Strait of Hormuz at the beginning of March triggered immediate disruptions to shipping and exports across the Gulf. Tankers were stranded, insurance costs surged and markets began pricing in the possibility of extended supply constraints.
Oil prices reacted quickly. By 5 March 2026, Brent crude had climbed into the mid-$80s per barrel after several consecutive days of gains as markets attempted to price the scale and duration of the disruption. Energy markets also began to show stress in refined products, freight costs and LNG supply.
Why Asia is particularly exposed
While oil is a global market, the exposure is not evenly distributed.
Asia relies heavily on Middle Eastern oil flows, and much of that supply passes through the Strait of Hormuz. Any prolonged disruption therefore affects Asian economies disproportionately.
Thailand provides a useful example. Around half of Thailand’s oil imports normally pass through the Strait of Hormuz, making the country one of the more exposed economies in the region when shipping through the Gulf is disrupted.
Energy is already a meaningful macroeconomic variable for Thailand. Net oil imports account for roughly 5% of GDP, meaning large price movements can quickly affect trade balances, inflation and the broader economy.
The Thai government responded quickly once the Hormuz closure became clear. Domestic oil exports were temporarily halted, except for deliveries to Laos and Myanmar. The national energy company PTT was instructed to secure alternative supply from markets such as Malaysia, the United States and Africa.
To stabilise domestic fuel prices, the government capped the retail price of diesel at 29.94 baht per litre for fifteen days using the state-managed Oil Fuel Fund.
Thailand currently holds roughly 65 days of oil reserves, but officials estimate this could extend to around 95 days once replacement cargoes arrive. At the same time, the energy regulator approved three spot LNG cargoes to compensate for disrupted Qatari shipments.
Even with these measures, energy shocks can still filter through the economy. Economists estimate that every 10% rise in oil prices worsens Thailand’s current account balance by around half a percent of GDP. That gives a good sense of how quickly energy markets can influence macroeconomic conditions.
One of the main reasons oil matters geopolitically is geography. Large volumes of global supply must move through a small number of chokepoints. The most important of these is the Strait of Hormuz, which sits between Iran and the Gulf states.
In normal conditions, roughly a fifth of the world’s oil supply passes through this narrow shipping route. That means disruption there can very quickly become a global economic issue rather than just a regional one. It is one of the clearest examples of how a physical bottleneck can turn energy supply into a geopolitical pressure point.
Recent events have illustrated this vividly. Iran’s closure of the Strait of Hormuz at the beginning of March triggered immediate disruptions to shipping and exports across the Gulf. Tankers were stranded, insurance costs surged and markets began pricing in the possibility of extended supply constraints.
Oil prices reacted quickly. By 5 March 2026, Brent crude had climbed into the mid-$80s per barrel after several consecutive days of gains as markets attempted to price the scale and duration of the disruption. Energy markets also began to show stress in refined products, freight costs and LNG supply.
Why Asia is particularly exposed
While oil is a global market, the exposure is not evenly distributed.
Asia relies heavily on Middle Eastern oil flows, and much of that supply passes through the Strait of Hormuz. Any prolonged disruption therefore affects Asian economies disproportionately.
Thailand provides a useful example. Around half of Thailand’s oil imports normally pass through the Strait of Hormuz, making the country one of the more exposed economies in the region when shipping through the Gulf is disrupted.
Energy is already a meaningful macroeconomic variable for Thailand. Net oil imports account for roughly 5% of GDP, meaning large price movements can quickly affect trade balances, inflation and the broader economy.
The Thai government responded quickly once the Hormuz closure became clear. Domestic oil exports were temporarily halted, except for deliveries to Laos and Myanmar. The national energy company PTT was instructed to secure alternative supply from markets such as Malaysia, the United States and Africa.
To stabilise domestic fuel prices, the government capped the retail price of diesel at 29.94 baht per litre for fifteen days using the state-managed Oil Fuel Fund.
Thailand currently holds roughly 65 days of oil reserves, but officials estimate this could extend to around 95 days once replacement cargoes arrive. At the same time, the energy regulator approved three spot LNG cargoes to compensate for disrupted Qatari shipments.
Even with these measures, energy shocks can still filter through the economy. Economists estimate that every 10% rise in oil prices worsens Thailand’s current account balance by around half a percent of GDP. That gives a good sense of how quickly energy markets can influence macroeconomic conditions.
How oil transmits into financial markets
Oil matters to investors for reasons that go far beyond the energy sector.
The most obvious channel is inflation. When oil rises sharply, transport costs increase, shipping becomes more expensive and businesses face higher production costs. These effects eventually feed into consumer prices.
That matters because inflation influences central bank policy. If higher energy prices push inflation higher or keep it elevated for longer, interest rates may remain higher than markets expect. Bond yields, equity valuations and currency markets all respond to that shift.
Another transmission mechanism is corporate profitability. Higher fuel prices increase costs for airlines, logistics companies, manufacturing firms and many consumer businesses. At the same time, energy producers often benefit from higher prices.
This is why oil shocks can lead to sector rotation in equity markets. Energy companies tend to outperform while fuel-intensive sectors often struggle.
Even if an investor does not directly own oil, their portfolio can still be exposed to these dynamics.
Where oil appears in a portfolio even without direct exposure
Many investors assume that if they do not own oil futures or commodity funds, they are not exposed to oil. In reality, oil influences portfolios through several indirect channels.
First, most global equity portfolios include energy companies through index exposure. The energy sector may represent a relatively small allocation in global indices, but its performance can still influence overall returns during periods of sharp price movement.
Second, oil affects inflation expectations. Fixed-income investments are particularly sensitive to this. If higher oil prices cause inflation expectations to rise, bond yields may increase and bond prices may fall.
Third, oil affects the real economy. Higher energy prices reduce disposable income for households and increase operating costs for businesses. These effects ripple through earnings, growth expectations and market sentiment.
In other words, oil is not just another commodity. It is one of the key variables that link geopolitics, macroeconomics and financial markets.
Why this matters for long-term investors
For long-term investors, the lesson is not that portfolios should constantly attempt to trade oil prices. Commodity markets are volatile and notoriously difficult to predict.
The more important lesson is that portfolios should be constructed with an awareness of the broader economic forces that influence markets.
Energy shocks can change inflation expectations, alter central bank policy and shift sector leadership within equities. They can also influence currencies, trade balances and economic growth, particularly in energy-importing regions such as Asia.
That is why diversification and careful asset allocation remain essential. A well-constructed portfolio should be able to absorb shocks that originate outside the financial system itself.
At Brigantia, we believe that financial planning and investment strategy must always be considered together. Markets do not operate in isolation from geopolitics or the real economy. Oil is one of the clearest examples of that connection.
Events in a narrow shipping channel thousands of miles away can influence inflation, markets and living costs across the world. Understanding those linkages helps ensure portfolios remain resilient, even when the headlines become more dramatic.
Oil matters to investors for reasons that go far beyond the energy sector.
The most obvious channel is inflation. When oil rises sharply, transport costs increase, shipping becomes more expensive and businesses face higher production costs. These effects eventually feed into consumer prices.
That matters because inflation influences central bank policy. If higher energy prices push inflation higher or keep it elevated for longer, interest rates may remain higher than markets expect. Bond yields, equity valuations and currency markets all respond to that shift.
Another transmission mechanism is corporate profitability. Higher fuel prices increase costs for airlines, logistics companies, manufacturing firms and many consumer businesses. At the same time, energy producers often benefit from higher prices.
This is why oil shocks can lead to sector rotation in equity markets. Energy companies tend to outperform while fuel-intensive sectors often struggle.
Even if an investor does not directly own oil, their portfolio can still be exposed to these dynamics.
Where oil appears in a portfolio even without direct exposure
Many investors assume that if they do not own oil futures or commodity funds, they are not exposed to oil. In reality, oil influences portfolios through several indirect channels.
First, most global equity portfolios include energy companies through index exposure. The energy sector may represent a relatively small allocation in global indices, but its performance can still influence overall returns during periods of sharp price movement.
Second, oil affects inflation expectations. Fixed-income investments are particularly sensitive to this. If higher oil prices cause inflation expectations to rise, bond yields may increase and bond prices may fall.
Third, oil affects the real economy. Higher energy prices reduce disposable income for households and increase operating costs for businesses. These effects ripple through earnings, growth expectations and market sentiment.
In other words, oil is not just another commodity. It is one of the key variables that link geopolitics, macroeconomics and financial markets.
Why this matters for long-term investors
For long-term investors, the lesson is not that portfolios should constantly attempt to trade oil prices. Commodity markets are volatile and notoriously difficult to predict.
The more important lesson is that portfolios should be constructed with an awareness of the broader economic forces that influence markets.
Energy shocks can change inflation expectations, alter central bank policy and shift sector leadership within equities. They can also influence currencies, trade balances and economic growth, particularly in energy-importing regions such as Asia.
That is why diversification and careful asset allocation remain essential. A well-constructed portfolio should be able to absorb shocks that originate outside the financial system itself.
At Brigantia, we believe that financial planning and investment strategy must always be considered together. Markets do not operate in isolation from geopolitics or the real economy. Oil is one of the clearest examples of that connection.
Events in a narrow shipping channel thousands of miles away can influence inflation, markets and living costs across the world. Understanding those linkages helps ensure portfolios remain resilient, even when the headlines become more dramatic.
