US Treasury Yields Hit 5.34% — Highest Since 2002, and Why Korea Feels It More

5.34%. That number hasn't shown up since 2002. US 10-year Treasury yields crossed that line, and the same day told two very different stories: the S&P 500 nudged higher while Korea's KOSPI slipped below the 6,950 mark. Same rate shock, opposite market moves. Here's what's going on.

Why Did Treasury Yields Spike This High?

This wasn't a US-only story. Fiscal jitters in France sent European yields sharply higher, and that pressure spilled into US Treasuries. On top of that, the ISM manufacturing prices index — a measure of how much companies are paying for raw materials — came in hotter than expected, reviving fears that inflation still isn't fully under control. When bond prices fall, yields rise; when yields rise, bond prices fall further. That self-reinforcing loop did a lot of the damage.

US Stocks Rose — So Why Did Korea Fall?

The key idea is opportunity cost. When safe government bonds are paying over 5%, why take the risk of owning stocks? That logic should hit both markets — but the US got two pieces of good news at once: Micron's blowout earnings and a dovish signal from the Fed's vice chair. Korea had no such cushion. Two structural factors make Korea especially vulnerable. First, foreign investors hold a very large share of KOSPI — when they sell, the index drops fast. Second, Korea's export-driven economy means rising US rates tend to weaken the Korean won. That creates a double hit for foreign investors: losses on the stocks themselves plus losses from currency moves. It's rate pain and currency pain at the same time.

The Fed Might Pause — Does That Mean Things Get Better?

Fed Vice Chair Philip Jefferson said the Fed needs 'more time' before deciding on another hike, pushing market odds of an October pause up to around 70%. That's a relief — but it's easy to misread what a pause actually means. A pause is not a cut. Holding rates steady at 5.34% is not the same as bringing them down. Businesses and households still carry the full weight of high borrowing costs. Markets may breathe easier for a moment, but the high-rate environment itself isn't going anywhere soon.