Ep 399: The Forever Test: Probably the most important concept investors must understand

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In this episode, Stuart explores what he believes is the single most important principle in long-term investing: choosing assets that are most likely to deliver the highest average return over the next 20–30+ years, and ideally much longer.

He explains why successful investors focus on lifetime compounding rather than short-term market noise, and how the real power of compounding only becomes obvious after decades of patience. Stuart walks through why investment decisions should always be framed around the question: Would I be comfortable owning this asset forever?

The discussion also covers the practical levers investors can control to maximise long-term outcomes. That includes minimising fees and tax drag so more returns can compound, selecting assets where growth is driven largely by unrealised capital appreciation, and structuring ownership correctly from the beginning.

Stuart also highlights the often-overlooked behavioural side of investing. The best investments are not just those with strong fundamentals; they are the ones that require minimal time, emotional energy, and decision-making so investors can stick with them through market cycles.

Finally, he explains how this principle applies across asset classes from ETFs built around durable indexes to investment-grade property in supply-constrained locations, and why resisting short-term “shiny object” strategies is essential for building meaningful wealth over time.

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This podcast provides general information about finance, tax and credit. It doesn't take into account your specific objectives, financial situation or needs, so you need to assess whether it's relevant to your circumstances before acting on it. If you're not sure, speak to a licensed, trustworthy professional.