On the 4th, the KOSDAQ market's regular session ended with sharp gains, driven by a broad rally across major sectors including biotech, semiconductors, and secondary batteries. Investor sentiment recovered rapidly, drawing in buying pressure, and a 'buy-side sidecar'—a mechanism that temporarily suspends program buy orders—was triggered during the session. The KOSDAQ index closed at 780.72, soaring 43.37 points (5.88%) from the previous trading day.

The top 10 stocks by market capitalization all trended higher, leading an overall improvement in investor sentiment. In particular, the strength of bellwether stocks representing major sectors stood out.

■ Biotech Bellwethers Lead with Highest Gains

The upward trend was most pronounced in the biotech sector. Alteogen, the largest by market cap, closed at 347,000 won, up 9.29% from the previous trading day. HLB surged 11.17% to 34,350 won, while ABL Bio (80,400 won, +13.24%) and RigaCeut Bio (109,900 won, +15.20%) recorded the highest gains among top market-cap stocks.

■ Secondary Batteries, Robotics, and Semiconductor Equipment Rally in Tandem

Secondary battery and robotics-related stocks also showed strong momentum. EcoPro (82,000 won, +5.94%) and EcoPro BM (102,500 won, +5.89%) posted significant gains, and Rainbow Robotics, a leading robotics stock, rose 1.85% to 467,000 won.

Semiconductor equipment-related stocks also rose across the board, reflecting improved investor sentiment. Jusung Engineering (136,000 won, +6.42%), along with Lintec Korea (64,400 won, +4.89%) and Wonik IPS (96,500 won, +2.99%), all climbed simultaneously.

[This article is for reference in making investment decisions and does not recommend buying or selling any specific stock. Losses and responsibilities arising from investments rest entirely with the investor.]