The wildest stock market in the world

The “sell America” trade was a short-lived fad that graced all of our newsfeeds amid the Liberation Day chaos. And while that trend didn’t exactly halt the S&P 500’s record run, it did pique our interest—if you aren’t going to invest in the US, then where should you put your money?

South Korea’s winning streak

One investment that you would have been happy to own this year was the South Korean Kospi, which is basically the South Korean version of the S&P 500. The Kospi gained tk% this year—making it the world’s top performing index in 2025—compared to the S&P 500’s tk% return. 

That’s especially impressive when you consider that over the past three years, the index traded below a price-to-book ratio of one, according to the Financial Times, which is certainly no vote of confidence.

Part of what’s driven this year’s turnaround is a slew of corporate governance reforms, which were enacted to specifically improve stock market valuations. But perhaps an even bigger driver has been excitement about the country’s AI stocks: Specifically, Samsung Electronics and SK Hynix, which have jumped tk% and tk%, respectively, in 2025. Both firms signed a deal with the king of AI startups, OpenAI, to supply semiconductors for the company’s Stargate data center buildout.

A whole new level of retail trading

But while South Korea’s market made a serious comeback this year, it also encouraged some of the riskiest retail behavior we’ve seen to date.

The South Korean stock market has a reputation for being an especially volatile playground for meme stock mania—so much so that nearly half of its daily turnover is from speculative retail investors, according to the FT. And like the retail crowd anywhere, South Korean investors’ appetite for risk, betting, and general debauchery has only ramped up over the past year.

It’s gotten so bad that regulators there are making brokerages show investors a training video about the risks of leveraged and inverse ETFs before they’re allowed to actually buy those funds.

While the wackiness may seem a world away, South Korean traders are bringing their talents to Wall Street, drastically increasing their holdings in US stocks as the market becomes more and more gamified. South Korean traders’ holdings in US stocks have nearly doubled over the past year to reach a record $170 billion, according to the FT.

At least Americans aren’t the only ones turning our financial system into one giant slot machine.—LB