As the KOSPI index surpassed the intraday record high of the 4,500 level on the 6th, the tilt toward domestic large caps is deepening. The contribution of Samsung Electronics and SK hynix, which led this rally, reached 88%, effectively allowing the two stocks to monopolize the domestic market rally.
As of the 6th, KOSPI market capitalization stood at 3,738 trillion won, with the combined weight of Samsung Electronics (22%) and SK hynix (14%) exceeding 36%. This is a steep expansion compared to Dec. 5, when total market cap was 3,381 trillion won and the two stocks' combined weight was 31% (Samsung Electronics 19%, SK hynix 12%).
The KOSPI index jumped 12.34% over the past month, from 4,028.51 points (p) to 4,525.48p. During this period, Samsung Electronics and SK hynix shares soared 32.16% and 33.95%, respectively, backed by foreign buying.
The market caps of Samsung Electronics and SK hynix rose from 1,038 trillion won to 1,351 trillion won. Based on this, calculating the contribution of the two stocks (increase in Samsung Electronics and SK hynix market cap/increase in KOSPI market cap) shows they accounted for 87.56% of the KOSPI's gains over the past month.
Even on a sector basis, the KOSPI electrical and electronics index surged 24.37% over the past month, and the KRX Semiconductor index jumped 25.37%, underscoring the semiconductor sector's solo lead.
With the tilt toward large semiconductor stocks standing out, some are voicing caution about future volatility. The securities industry says that because gains are concentrated in specific names, if market volatility expands, the KOSPI's pullback could be larger than expected.
Shinhan Investment & Securities noted that while December exports rose 13.4% on-year, segments excluding semiconductors (42.3%) and computers (36.7%) saw only low single-digit growth. Ha Geon-hyeong, a researcher at Shinhan Investment & Securities, said, "Through last month, export scale renewed monthly record highs for seven consecutive months," but added, "Petrochemicals, general machinery, and steel continue to suffer simultaneous weakness in prices and volumes."
The "temperature gap" within the index rally is also evident in the number of names. On the 6th, even as the KOSPI index crossed the 4,520 level and expectations grew for an unprecedented break of 5,000p, decliners and flats (534) far outnumbered advancers (398). The KODEX 200 Equal Weight exchange-traded fund (ETF), which spreads investment equally rather than by market-cap weight across KOSPI200 constituents, finished the same day at 15,620 won, failing to surpass the record high of 15,880 won set in November last year.
That said, this year's outlook for semiconductor earnings is relatively bright. Major brokerages are raising their KOSPI targets in succession based on improving semiconductor earnings and foreign buying. Yuanta Securities Korea raised its projected KOSPI range for this year to 4,200–5,200 points, while Kiwoom Securities even saw the possibility of surpassing 6,000 points in an optimistic scenario.
A securities industry official said, "The index is rising, but we are in a phase of deepening differentiation by stock and sector, so it is necessary to check whether the concentration in large semiconductor stocks can ease."