South Korea Urged to Reconsider Treasury Bond Strategy as Global Shift Away from Long-Term Debt Accelerates
South Korea faces mounting pressure to overhaul its treasury bond issuance framework as major economies worldwide shift away from long-term debt instruments toward shorter maturities. Analysts argue that the country's current structure, heavily weighted toward 30-year bonds, requires urgent reassessment in light of weakening demand from core institutional investors and evolving global market dynamics.
According to a report released on the 26th by the Korea Capital Market Research Institute, Jung Whayoung, a research fellow specializing in fixed income markets and macroeconomy, highlighted fundamental changes reshaping government debt markets globally. Central banks in major countries have been reducing their government bond holdings even as fiscal demands remain elevated, forcing private investors to absorb substantially larger volumes of debt.
The trend has proven particularly challenging for long-term bonds. Weakening investment appetite for extended maturities and rising long-term yields have prompted governments to recalibrate their issuance strategies, matching supply more closely to actual market demand across different maturity segments.
United States Emphasizes Short-Term Instruments
The United States has emerged as a leading example of this strategic pivot. Beginning in 2023, the U.S. Treasury deliberately shifted issuance toward shorter-term bills, primarily driven by rapidly rising interest rates as policymakers sought to manage exposure to high-yielding long-term debt. Data from U.S. Treasury auctions reveals that the combined share of 2-, 3-, and 5-year bonds climbed from 55.5% in 2022 to 61.9% between January and August this year.
The expansion of short-term treasury bills with maturities of one year or less has been particularly pronounced. Supported by strong demand from money market funds and other institutional investors, short-term instruments now represent 22.8% of total outstanding U.S. Treasury debt as of last month. The U.S. Treasury market stood at $26 trillion in August 2024, marking a 51% increase from December 2019, with the Federal Reserve having absorbed roughly 60% of the debt increase during 2020-2021 through quantitative easing before beginning to reduce holdings.
U.S. money market funds held $2.7 trillion in U.S. Treasuries as of October 2024, representing 38% of total MMF assets. This substantial allocation reflects both large inflows into government funds and regulatory constraints that make short-term securities particularly attractive. Money market funds can only invest in securities with remaining maturities of no more than 397 days, making Treasury bills with one-year-or-less maturities especially appealing investment options.
However, the strategy carries inherent risks. Overreliance on short-term instruments could increase refinancing risks and raise interest cost burdens if rates continue climbing. The U.S. Treasury Borrowing Advisory Committee recommended in November 2020 that the Treasury maintain T-bills in a range of 15 to 20 percent of outstanding debt over the medium to longer term, suggesting guardrails for maintaining portfolio balance.
Japan and UK Face Similar Pressures
Japan and the United Kingdom are implementing their own adjustments in response to declining long-term bond demand. The Bank of Japan began quantitative tightening in 2024, gradually reducing government bond purchases by trimming monthly buying by 200 billion yen each quarter. This shift, combined with slowing demand from life insurance companies for ultra-long-term bonds, has led Japanese authorities to reduce issuance of 20-, 30-, and 40-year bonds.
In the United Kingdom, changing dynamics within defined benefit pension schemes have fundamentally altered the government bond market landscape. UK DB pension schemes hold approximately £1.4 trillion in assets under management, with around 69% invested in bonds as of 2023. This represents a dramatic shift from the pre-2012 period when equities dominated these portfolios. Following the September 2022 mini-budget crisis, many DB schemes were forced to sell government bond holdings to meet cash calls from lenders, accelerating a reorientation toward corporate bonds over gilts.
The UK government responded decisively to weakening long-term bond demand from these institutional investors. The share of long-term fixed-rate government bonds was reduced from 28.5% in the 2022-2023 fiscal year to just 9.1% planned for the 2026-2027 fiscal year, while medium- and short-term bond proportions increased correspondingly.
South Korea's Structural Challenge
South Korea confronts similar headwinds in its domestic market. Insurance companies, historically the primary purchasers of ultra-long-term bonds, have significantly extended their asset durations in recent years. Combined with improvements in solvency ratios driven by rising market interest rates, these institutions now have reduced need for additional ultra-long-term bond purchases.
Jung noted that the government's decision to reduce the share of 30-year bond issuance by 8 percentage points this year compared to last year represents a measure aligned with changed demand conditions. However, she emphasized the need for careful balancing, given that 30-year bonds still account for 24% of total treasury bond issuance—the largest share among all maturity categories.
The researcher stressed the importance of seeking an appropriate issuance mix that weighs both the benefits of enhancing long-term funding stability and the associated funding cost burdens. This balancing act becomes particularly critical as South Korea navigates evolving market conditions without the short-term instruments that provide flexibility to other major economies.
Case for Short-Term Bond Introduction
A significant gap in South Korea's current framework is the absence of treasury bonds with maturities of one year or less. The country currently issues conventional treasury bonds with maturities of 2, 3, 5, 10, 20, 30, and 50 years, but no shorter-term instruments. Jung argued that this omission prevents South Korea from fully utilizing investment demand from institutional investors managing short-term funds, particularly money market funds.
The introduction of short-term treasury bonds could diversify the investor base and provide new funding flexibility. Once issuance and trading of such instruments become established, Jung suggested, conditions could emerge for introducing variable-rate government bonds linked to short-term interest rates, further expanding the toolkit available to debt managers.
As global bond markets undergo fundamental restructuring, South Korea's approach to treasury bond issuance faces a critical juncture. The decisions made in coming months regarding maturity structure and instrument diversification will shape the country's debt management framework for years to come, with implications for funding costs, market stability, and fiscal flexibility.
