Chip Stocks Rebound: Korea's KOSPI Jumps 4%, Triggers Circuit Breaker as Samsung Rises 6% and Kioxia Soars 15%

What happened in Korea's stock market today, and what triggered the circuit breaker?

According to a cnyes report, chip stocks staged a broad rebound, with South Korea's stock market rising 4% and triggering a circuit breaker ¹. A Liberty Times (ltn) report provides the intraday sequence: the KOSPI opened with a gap-up, breaking through the 7,000-point level to open at 7,052.09 points, up 304.13 points or 4.5% ⁴. The index then continued climbing, reaching 7,158.63 points, up 410.67 points or 6.08%, which triggered the circuit breaker a second time, according to ltn ⁵.

How much did Samsung Electronics and SK Hynix shares gain?

The cnyes headline states Samsung Electronics rose 6% ². However, the ltn report, citing the same trading session on July 22, 2026, describes Samsung Electronics as up "more than 5%" ⁷ and SK Hynix as up "more than 7%" ⁶, attributing part of the index's advance to these two chipmakers. The two outlets present slightly different figures for Samsung — 6% versus "more than 5%" — while both agree the stock was among the session's biggest movers.

How strong was Kioxia's rally?

According to the cnyes report, Kioxia (鎧俠) was the standout performer among chip stocks, surging 15% ³. This was the single largest percentage gain cited across the evidence for any individual company in this rebound.

Did U.S. and Japanese markets rally too, reinforcing the chip rebound?

Per the ltn report, Japan's Nikkei Index also advanced, opening up 217 points at 66,449 points before climbing further to 67,409 points, a gain of 1,177 points or 1.77%, moving the index back above the 67,000 level ⁸. In the U.S. session the prior day (Tuesday, July 21, 2026), ltn reports all four major indices rose: the Dow Jones Industrial Average gained 385.38 points, or 0.74% ⁹; the S&P 500 rose 0.89% ¹⁰; and the Nasdaq climbed 1.29% ¹¹.

How did the Philadelphia Semiconductor Index perform before and after this week's rebound?

According to ltn, the Philadelphia Semiconductor Index (SOX) had fallen more than 20% from its late-June historical high as of last Friday, putting it into a bear market ¹². The same report notes the index then rose for two consecutive trading days, with Tuesday's session showing a 5.21% gain ¹³.

Key figures at a glance

What this means

Taken together, the evidence shows the chip-sector rebound was not confined to Korea. The Philadelphia Semiconductor Index's move from a 20%-plus bear-market decline last Friday to two straight days of gains, capped by a 5.21% jump on Tuesday (E12, E13), lines up chronologically with the U.S. market's broad Tuesday advance across the Dow, S&P 500, and Nasdaq (E9, E10, E11), followed by Wednesday's Nikkei climb past 67,000 ⁸ and the KOSPI's circuit-breaker-triggering surge to over 7,150 points (E4, E5). Within that Korean session, the two reports diverge slightly on Samsung Electronics' exact gain — 6% per cnyes versus "more than 5%" per ltn (E2, E7) — while both single out Kioxia's 15% jump ³ and SK Hynix's 7%-plus gain ⁶ as the sharpest individual moves, indicating the rebound was led by memory-chip and storage names rather than being evenly distributed across the sector.