Korean chip selloff after US midterms exposes 40% concentration risk

By Marcus Bennett

The KOSPI, South Korea's main stock index, fell more than 6 percent on Friday as SK hynix dropped 10.44 percent and Samsung Electronics lost 6.35 percent, according to the editorial. Trading in Seoul pushed the benchmark below 5,000 as investors sold the market's two benchmark heavyweights in panic.

The editorial described the session as "Black Friday," citing a frantic mix of a circuit breaker and sell-side sidecars, or temporary curbs for unusually sharp price moves. Other Asian indexes, including Taiwan's, also declined, but the editorial said Seoul's heavy semiconductor exposure amplified the market volatility.

The editorial's concentration figures gave a U.S. political shock an unusually direct route into Korean assets. SK hynix and Samsung Electronics account for about 40 percent of KOSPI market capitalization; the editorial also estimated that chips, including high-bandwidth memory and conventional memory chips, make up about 40 percent of South Korea's exports.

The same policy or spending shock can therefore reach equity values, export revenue and public finances through one industrial cluster. That structure explains why developments in Washington carried more weight in Seoul than in a more diversified market. It is Korea's core vulnerability.

What changed after the US midterms?

U.S. indexes that rose immediately after last week's midterm elections fluctuated on Friday, the editorial reported. It framed the reaction as a changed economic climate created by a shift in the U.S. political landscape and a new balance of power in Congress.

The editorial said optimism that the elections had reaffirmed the country's democratic values was tempered by concern about the Democrats' agenda to regulate artificial intelligence and restrict data-center construction. It described a second concern: investors were questioning whether the AI boom is a bubble and whether massive investment in the sector will ultimately generate profits.

Those doubts mattered for Korea because the editorial said aggressive AI investment and a sustained U.S. drive to build data centers had contributed to the strong performance of Korea's top chipmakers. When expectations for regulation, construction and returns moved against investors, the companies carrying roughly 40 percent of the KOSPI bore the heaviest selling.

The editorial said the market landscape had shifted along with the balance of power in the U.S. Congress. It also maintained that South Korea could not afford to lose its competitive edge in semiconductors, even as it warned that the boom's profitability now faced open skepticism.

Why did the selloff become so severe?

The KOSPI's concentration made the losses unusually steep. SK hynix's 10.44 percent decline was nearly twice Samsung Electronics' 6.35 percent fall, and both occurred as the session brought a circuit breaker and sell-side sidecars. The measures confirmed the scale of the panic selling even as they attempted to slow it.

The selloff also intersected with domestic policy. The editorial said President Lee Jae Myung's strong pledge to tackle the so-called "Korea discount" pushed volatility higher. The term denotes the persistent undervaluation of Korean companies, and the plunge placed that valuation problem alongside a separate concern about financial stability.

For Seoul, the immediate task was to curb further selling, according to the editorial. It said senior officials from South Korea's economic, financial regulatory and monetary agencies convened to discuss emergency measures after the decline. That response targeted the panic described in the session rather than the wider structural problem.

What emergency measure did Seoul discuss?

Their options included a three-month exemption from collateral reserve requirements on loans to investors. The rule sets minimum security reserves for those loans, and the proposed exemption would temporarily remove that constraint for three months. The editorial said officials considered the change to curb further selling.

The editorial said the measure might bring some peace to investors, but warned that depressed and distrustful investors could remain wary of government intervention. It treated the proposal as a temporary response to panic, not a substitute for reforms intended to guard against future market shocks.

That distinction runs through the editorial's argument. A reserve-rule exemption can address the mechanics of a liquidation episode. It cannot, by itself, reduce the share of one industrial cluster in exports, reduce the weight of two stocks in the main index or replace the growth engines that must emerge as today's semiconductor cycle matures.

Is economic growth broadening the risk?

Korea's headline numbers remain strong. The editorial reported a forecast for the national economy to grow by around 3 percent this year, while total exports are on track to reach a record $1 trillion as early as this month. Those figures show scale, but the editorial's policy argument concerned the composition of that growth.

The numbers were stark. Semiconductors, including high-bandwidth memory and conventional memory chips, account for an estimated 40 percent of the country's exports. SK hynix and Samsung Electronics together make up about 40 percent of the KOSPI's total market capitalization. The numerical symmetry does not remove the risk; it links equity-market concentration to trade concentration.

On the editorial's assessment, that structure cannot keep driving sustainable growth or generating the surplus profits that fill government coffers. Its answer was not to abandon chips. South Korea cannot afford to lose its competitive edge, and the country must continue investing in semiconductor research, development and innovation.

Government plans for three major semiconductor projects reflect that commitment. The editorial said profits from the current chip boom gave the government confidence to pursue its "three megaprojects," but it also argued that current earnings do not replace the need for future growth engines. That requires both protecting the existing industry and reducing the economy's dependence on it.

Which reforms can widen the economic base?

The editorial identified two complementary paths beyond semiconductors:

• Deregulate automotive, shipping and battery industries. The editorial said deregulation could revive these established sectors and give them a larger role in the next phase of growth.
• Support robotics, biotechnology and small modular reactors. The editorial described these emerging sectors, including compact nuclear systems assembled in modules, as needing an environment in which they could become new engines of the economy.

Neither path displaces the chip industry in the editorial's proposal. Its diversification rests on continued semiconductor investment, including the three major projects, while deregulation revives established industries and emerging fields become additional growth engines.

The proposal therefore has two time horizons. The semiconductor projects protect the current earnings base; deregulation and new sectors seek to spread growth beyond it. That sequencing matters because the editorial estimated that chips still represent about 40 percent of exports and two firms about 40 percent of KOSPI value.

What should the Lee administration prioritize?

Structural answers take longer. The editorial acknowledged that structural reforms take time and said the current export cycle gives the government room to act. It urged the Lee administration to devote greater attention to South Korea's long-term economic vulnerabilities and their implications instead of concentrating heavily on domestic political battles.

One such battle was the recent passage of a bill authorizing a special counsel investigation into allegations of fabricated indictments targeting President Lee and others. The editorial treated that emphasis as a diversion from diversification, semiconductor investment and financial stability. Its criticism connected the market response to the administration's allocation of attention, not merely to the mechanics of one trading session.

The coming test is whether the government can turn the projected $1 trillion export cycle into broader, durable growth. Semiconductors account for about 40 percent of exports and the two leading chipmakers for about 40 percent of KOSPI value; the proposed reforms seek to change that concentration while preserving the competitive edge that currently underwrites both figures.