South Korea sells $1.7B in currency stabilization bonds at record-low spreads

South Korea just borrowed money from international markets at the cheapest rate in its history. On October 23, the Ministry of Economy and Finance issued approximately $1.7 billion in foreign exchange stabilization bonds, locking in a spread of just 17 basis points over US Treasuries on its dollar-denominated tranche.

For context, that spread was 25 basis points in 2024. In the world of sovereign debt, shaving 8 basis points off your borrowing costs is the equivalent of a credit score upgrade that actually matters.

Breaking down the bond sale

The issuance came in two flavors. The first was a $1 billion tranche of 5-year dollar-denominated bonds, priced at a yield of 3.741%. That 17-basis-point spread over US Treasuries represents a new record low for South Korean sovereign debt.

The second portion consisted of roughly $700 million equivalent in yen-denominated bonds. These carried maturities ranging from 2 to 10 years and were priced at yields in the 1% range.

Combined with earlier issuances this year, South Korea’s total FX bond sales for 2025 have now reached $3.4 billion. That’s the highest annual total since 1998, a year when South Korea was still clawing its way out of the Asian financial crisis and desperately needed foreign currency reserves.

FX stabilization bonds aren’t regular government debt used to fund budget deficits. These instruments are specifically designed to build up foreign currency reserves that can be deployed to defend the Korean won during periods of market stress.

Why global investors are piling in

The record-low spreads tell a clear story about how international capital markets view South Korea’s creditworthiness right now. When investors demand barely any premium above the risk-free rate to hold your debt, they’re essentially saying they consider your bonds almost as safe as US Treasuries.

The yen-denominated tranche adds another dimension. By diversifying its borrowing across currencies, Seoul reduces its exposure to any single exchange rate. Issuing yen bonds at yields around 1% is remarkably cheap funding by any historical standard, even accounting for currency hedging costs.