There’s a dangerous kind of comfort spreading through the investing world

It’s called market monomania — the quiet conviction that the only stock markets worth investing in are U.S. ones. S&P 500, Nasdaq, Big Tech, the Magnificent Whatever — it’s all become shorthand for ‘the market’” And in many portfolios, that’s literally true. Everything else — Europe, Asia, emerging markets, even small caps — is treated as background noise

But that comfort? It’s an illusion. And a fragile one

The American centre of gravity

It’s easy to see how we got here

For over a decade, the U.S. market has crushed almost every rival. The tech boom, dollar dominance, and sheer global brand power made diversification look old-fashioned — even naïve. Why bother owning laggards when you can just buy the winners and watch the line go up? Every dip was a buying opportunity. Every Fed pivot a starting gun. Every global shock yet another reason for capital to run home to U.S. assets

But that’s precisely how monomanias are born — not through greed, but through habit

The risk of the single story

The U.S. market isn’t invincible. It’s concentrated — absurdly so

A handful of companies now drive an outsized share of global equity returns. A few percentage points of GDP growth, a few basis points of inflation, a whisper from the Fed — and the whole narrative swings. When your portfolio lives and dies by the same handful of names, you’re not diversified. You’re just levered to a story that’s been working so far

History doesn’t treat those stories kindly. Japan in the 1980s looked unstoppable. The Nikkei still hasn’t recovered

The world is wider than Wall Street

There are companies in Asia building the infrastructure for the next decade. European firms with fortress balance sheets and global reach. Emerging markets that are messy, yes, but full of demographic firepower and innovation

Diversification isn’t about pessimism — it’s about humility. It’s about admitting that the future might not rhyme with the past decade of U.S. dominance

Don’t mistake familiarity for safety

Most investors think they’re chasing returns, but often they’re chasing comfort. The U.S. feels safe because it’s familiar — its brands, its language, its data transparency. But comfort and safety aren’t the same thing. Overreliance on any one market — however mighty — is still concentration risk in disguise

So take a breath. Zoom out. Rebalance

As always, caveat emptor!