The myth of the one great stock
Every generation has a company that looks unbeatable. It has the brand, the market share and years of good numbers behind it. Owning it feels less like investing and more like common sense.
The trouble is that a company's past strength doesn't protect its future. Structural decline is real: a technology shift, a change in regulation, a new competitor or a slow loss of pricing power can permanently reset what a business is worth. Household names in Australia and overseas have spent a decade or more going sideways while the wider market kept compounding.
That's not a reason to avoid good companies. It's a reason not to let one of them carry your whole plan.
Diversification is often called the only free lunch in investing — it can reduce the depth of your falls without you having to predict anything.
Compensated versus uncompensated risk
Not all risk pays you. Markets reward you for taking broad risk — the risk of owning listed businesses, or lending money through bonds — because that risk can't be avoided by anyone. Over long periods, bearing it is what produces a return.
Single-company risk is different. It can be removed almost for free simply by owning more companies, so the market doesn't pay you extra to carry it. That's what "uncompensated risk" means: you take the extra bumpiness, but you're not paid for it.
Put plainly, holding one company instead of thousands adds risk without adding expected return. Removing it is one of the few genuinely free improvements available to an investor.
Same return, calmer ride
Two portfolios can end up in a similar place, yet only one is easy to live through along the way
The maths of compounding
Losses hurt more than equivalent gains help. If $100,000 falls 50% to $50,000, it needs a 100% gain just to get back to where it started. A 16% fall only needs about 19% to recover.
This is why avoiding deep falls matters more than catching occasional spectacular years. Compounding rewards consistency, and every deep hole you avoid is growth you never have to earn back.
What it takes to recover
| If your portfolio falls | You need this gain to break even | Years at ~8% p.a. |
|---|---|---|
| -10% | +11% | About 1.4 years |
| -20% | +25% | About 2.9 years |
| -35% | +54% | About 5.6 years |
| -50% | +100% | About 9 years |
How we use this in practice
We build portfolios so that no single holding, sector or country can derail your plan. Growth assets do the long-term work, defensive assets soften the falls, and position sizes are set so being wrong about any one thing is survivable.
If you already hold a large single position — from an employer plan, an inheritance or a long-held family holding — the conversation is usually about unwinding it thoughtfully, with tax and timing in mind, rather than all at once.