The US Bond Buyback Lasted One Day — Why Governments Can't Just Control Interest Rates

In August 2025, the US Treasury took an unusual step. It conducted a 'buyback' — repurchasing government bonds already circulating in the market. A government bond is essentially an IOU the government issues when it needs to borrow money. By buying these back, the Treasury hoped to inject cash into the market and push interest rates lower.

What exactly is a buyback?

A buyback means repurchasing something you previously sold. When the Treasury buys bonds from the market, bond prices rise and interest rates fall — they always move in opposite directions. Think of it this way: the higher the bond price, the lower the interest rate investors receive. That's the lever Treasury Secretary Bessent decided to pull.

What did Secretary Bessent actually do?

The Treasury purchased billions of dollars worth of bonds from the open market. On the day of the announcement, long-term bond yields dipped briefly. Bessent expressed confidence, saying there were 'additional tools available.' But the very next day, rates climbed right back to where they started.

Why did the effect vanish in just one day?

When global investors believe the US economy remains shaky, they sell government bonds. Selling pushes prices down and rates up. No matter how many bonds the Treasury buys, if far more investors are selling, the effect gets wiped out almost immediately. The sheer scale of the market dwarfs any single government action.

What do high interest rates mean for my stocks?

Higher rates mean companies pay more to borrow money, which squeezes their profits — and lower profits put pressure on stock prices. Growth stocks (companies like Tesla or Nvidia that rely on future earnings) are especially sensitive to rising rates. When US long-term rates climb, foreign capital can flow out of Korean stocks as well.

Why does Korea get dragged along?

When US rates rise, dollar-denominated assets become more attractive. Global investors tend to sell stocks in emerging markets like Korea and shift into those dollar assets. This weakens the Korean won and can pull the KOSPI index lower. In short, US interest rates act as a thermometer for Korean markets.