Kospi Triggers Another Sidecar as Chip Rebound Stalls, Falls Over 6%

South Korea’s Kospi sank 6.45% Wednesday, from 6,869 to 6,426 points. The Korea Exchange activated a sell-side sidecar for the benchmark in response.

Program trading on Kospi-listed shares was suspended for five minutes at 9:06 a.m. local time. The halt interrupted a rebound that had lifted the index in prior sessions.

Chip Stocks Lead the Sell-Off

A sell-side sidecar triggers automatically when Kospi 200 futures fall 5% or more for one minute. It pauses program sell orders for five minutes, without halting individual stock trading.

Samsung Electronics and SK Hynix, which together drive much of the index’s weighting, led Wednesday’s decline. Investors tracked overnight losses on Wall Street, where chip stocks also sold off.

SK Hynix’s U.S.-listed shares fell 9.20% to $155.62 in Tuesday’s session. The stock slipped another 1.38% in after-hours trading, signaling further pressure into Wednesday.

The drop extends a volatile stretch for Korea’s chip-heavy market. The index had staged a sharp rebound in recent weeks following earlier sidecar and circuit-breaker activations this year.

Oil Prices and Iran Tensions Weigh on Sentiment

Rising oil prices and bond yields added pressure across the region. A 60-day U.S.-Iran memorandum expired Monday without a broader agreement, and President Donald Trump ruled out further talks.

“There are no talks or conversations going on, or scheduled, with the Islamic Republic of Iran.”

Trump made the remark in a Truth Social post Tuesday. He also said the U.S. naval blockade remained in force, even as he described the Strait of Hormuz as open and operating.

The renewed geopolitical standoff has kept oil markets on edge. Brent crude gained 0.75% to $91.50 a barrel Tuesday, adding to inflation worries.

An Iranian official reportedly warned Tehran could shift to a “fully offensive” posture should diplomatic efforts collapse. Back-channel contact reportedly remains possible despite the stalled formal talks.

Japan’s Nikkei 225 also declined Wednesday, falling more than 2%. The chip sell-off spread across Asian markets, with Tokyo names tracking the same overnight U.S. losses.

Wednesday’s sidecar marks another halt in a year already defined by repeated trading curbs. Samsung and SK Hynix now face pressure to stabilize before Thursday’s session.