3 Things to Keep in Mind If You Want to Build a Sustainable Investment Portfolio

Wall Street is an echo chamber that seems focused on getting investors to think only about the short term. That's not a sustainable investment approach. You need to think in decades, not days. There's no better example of that right now than the geopolitical conflict in the Middle East. A look at ExxonMobil (NYSE: XOM) can provide you with three examples you should apply to your entire investment portfolio.

1. Exxon knows that short-term trends come and go

Exxon will benefit from rising oil and gas prices, just as other energy stocks will. However, management isn't losing sight of the real goal: surviving and growing over the long term. For example, the company spent $26.4 billion on capital expenditures in 2025, as it looks to focus on its best assets. By 2030, Exxon expects what it calls "advantaged" assets to make up 65% of its production.

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Exxon will be happy to benefit from the windfall provided by high oil prices in 2026, but that 2030 goal is still years away. And management isn't going to stop reaching for that longer-term goal just because oil prices are high right now. In fact, it is likely to use the outsize profits to support that long-term goal. Like Exxon, you need to think long-term when making your investment decisions.

2. Exxon is diversified on purpose

Another key part of Exxon's business is its integrated approach. It has exposure across the entire energy value chain, helping soften the impact of swings in the inherently volatile energy sector. It is also geographically diversified, so that events in one region don't derail the entire business. That's how the company has managed to increase its dividend annually for decades, despite the often-dramatic swings to which the energy sector is prone.

You should diversify your portfolio, too. For example, buying only oil stocks while oil prices are high would be a very bad choice. Eventually, oil prices and oil stocks will fall. A better option would be to diversify your portfolio across the entire market. Your mix should probably include an energy component, perhaps even Exxon specifically, but energy should only be one part of a larger whole.

3. Exxon has a strong balance sheet

Lastly, Exxon understands that it needs a strong financial foundation to navigate the ups and downs it will face in the energy sector. Notably, it ended 2025 with an industry-leading debt-to-equity ratio of 0.2x. Having a strong balance sheet gives Exxon the flexibility to add leverage during industry downturns so it can continue to support its business and dividend until the energy market recovers.

You should take the same care with your finances, so a bad market won't force you into a precarious financial position. Notably, avoid leverage, particularly margin debt, so you don't have to sell assets in bear markets. And have a financial safety net (perhaps three to six months' worth of living expenses in cash), so you can handle unexpected events in relative stride. The best time to fortify your finances is during the good years, knowing that the bulwark you build will support you through the inevitable bad years.

Exxon knows a thing or two about long-term investing

Exxon is an incredibly well-run company. It thinks long-term because it knows that short-term trends come and go. It is diversified because it understands that putting all of your eggs in one basket is a huge risk. And it has long focused on having a strong financial foundation, because that gives it the wherewithal to survive hard times. All of that may entice you to buy Exxon for your portfolio, but don't overlook the lessons that Exxon's business has to offer for your personal finances.

Reuben Gregg Brewer has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.