Did the KOSPI just initiate a bubble burst?KOSPI Composite IndexKRX:KOSPIGivtrade_Group The KOSPI triggered a market-wide circuit breaker today, halting trading the 8th time this has happened in 2026 alone. Samsung Electronics and SK Hynix, which together account for more than 50% of the entire Korean market, are down sharply, dragging the whole index with them. This is the structural problem: when two stocks make up over half your benchmark, the index isn't really diversified it's a leveraged bet on two companies. A 12-13% move in Samsung and SK Hynix doesn't just hurt those positions, it takes the entire KOSPI down with it, regardless of what the other 900+ listed companies are doing. That's exactly what's playing out today. Price has now dropped into Support Area 1 at 6,334.34 — the first real level worth watching. A hold here could stabilize things short-term. But if this breaks, the next real floor is Support Area 2 at 5,045.05, which lines up with the launch zone from earlier this year. A move to that level would mean giving back a huge chunk of the 2026 rally. The knock-on effect is already spreading to the US: chip stocks are under pressure premarket on contagion from the Korean selloff and renewed concerns about AI infrastructure financing, Nvidia's structure in particular. Adding to the volatility: Citadel Securities is now floating the idea of a surprise rate hike at this week's FOMC meeting — arguing it would boost Fed Chair Warsh's inflation-fighting credibility. For retail traders: this is a reminder that index concentration cuts both ways. The same two stocks that powered KOSPI's rally this year are now the ones tearing it down. Watch how price behaves at 6,334 that's the level that tells you whether this is a shakeout or the start of something bigger.