Asian markets cracked on June 8, 2026, wiping out billions of dollars in value within hours. South Korea’s KOSPI index plunged nearly 9% within the first 20 minutes of trading, triggering a circuit breaker. Taiwan’s TAIEX dropped more than 2,600 points, with TSMC seeing its biggest intraday price fall on record. Japan’s Nikkei also slipped over 4%.
Even the US futures flashed deep red. At the same time, oil jumped above $93 a barrel, adding another layer of pressure to an already nervous market. But this was not a simple “global markets are down” story. The sell-off had three clear triggers which together turned a correction into a fast-moving global risk-off trade.
Let's break down the three separate shocks that converged in 72 hours causing global markets to fall, why Korea and Taiwan took the worst of it, and whether this is the AI trade cracking or just a very uncomfortable speed bump.
Why Did KOSPI Fall Today? The Triggers Behind Asian Markets Sell-Off
Most coverage today is leading with Iran. That's fair, but it's one piece of a three-part problem. Two other triggers hit AI and semiconductor stocks together:
Trigger 1: Broadcom’s Guidance Shock Hit Semiconductor Stocks First
Broadcom’s fiscal Q2 2026 numbers were not weak. Revenue and EPS beat analyst expectations. The problem was the outlook. Broadcom guided for Q3 AI chip sales of $16 billion, below the $17.2 billion analysts expected. It also did not raise its full-year 2026 AI semiconductor forecast.
That mattered because AI investors had become used to “beat-and-raise” quarters. Broadcom beat, but did not raise expectations enough. The reaction was sharp. The Philadelphia Semiconductor Index fell 10.3% on June 5, its worst single-day drop since March 2020, wiping out about $1.3 trillion in chip-sector market value. That set a weak tone for Asian chipmakers heading into Monday.
Trigger 2: US Jobs Data Revived Fed Rate Hike Fears
The second trigger was the US jobs report. May non-farm payrolls rose by 172,000, far above the Dow Jones estimate of 80,000. The unemployment rate stayed at 4.3%. A strong labour market usually means the US economy is still running hot. T
That makes rate cuts less likely, especially when inflation is still elevated and geopolitical uncertainty around the Iran war remains high. CME FedWatch showed markets raising the odds of a US rate hike by end-2026 to about 70%.
Higher rates bother markets for two reasons. First, borrowing becomes costlier for companies, which can hurt profits. Second, safe assets like government bonds become more attractive, so investors demand better returns from risky stocks. But, even after Monday's crash, South Korea's KOSPI is still up approximately 75% year-to-date in 2026. That context matters. This is a market that ran very hard. But the mechanics behind today's specific plunge deserve a closer look.
This hits high-growth stocks like Samsung, SK Hynix and Micron the hardest. AI and semiconductor companies are valued heavily on future earnings. When rates rise, those future profits are worth less in today’s terms. That is why these stocks can reprice very quickly when rate expectations change. Think of it like fixed deposits. If one FD offers 7% safely, a riskier option has to look much more rewarding to justify the risk. That is why rising yields can quickly hurt high-growth stocks, especially tech stocks.
But, even after Monday's crash, KOSPI is still up approximately 75% year-to-date in 2026. That context matters. This is a market that ran very hard. But the mechanics behind today's specific plunge deserve a closer look.
Trigger 3: Iran-Israel Conflict Pushed Oil Higher
On the night of June 7, Iran launched missiles at Israel in the first such strikes since a fragile ceasefire took effect in early April, raising the possibility of a return to heavy fighting. Iran's Revolutionary Guard stated the operation was "a warning," adding that "responses will be broader" if aggressions continue. Energy markets reacted fast. But two other triggers had already landed earlier in the week. All these triggers arrived within 72 hours. None had time to be absorbed before the next one hit.
| Index | Today's Drop | 5-Day Drop | YTD Performance |
| South Korea KOSPI | ~8.4% | ~11-12% | ~75% |
| Taiwan TAIEX | ~5-6% | ~7% | ~48% |
| Japan Nikkei 225 | ~3.5-4% | ~5% | ~23% |
| Nasdaq Composite (June 5) | 4.18% | ~6% | - |
| Philadelphia Semiconductor Index | 10.3% | ~12% | - |
Sources: Yahoo Finance, Bloomberg, Business Today, Focus Taiwan | Data as of June 8, 2026, intraday.
Why South Korea’s KOSPI Fell Harder Than Other Asian Markets
The sell-off was not just about weak semiconductor stocks. It became a chain reaction across three pressure points:
1. Index concentration: Samsung Electronics and SK Hynix together account for nearly half of the KOSPI’s total market value. TSMC alone accounts for over 40% of Taiwan’s TAIEX benchmark. That means South Korea and Taiwan are both heavily exposed to one sector: semiconductors. When that sector falls sharply, the entire index comes under pressure, even if other parts of the market are relatively stable.
2. Record retail margin debt: The bigger hidden problem in South Korea was borrowed money. As of June 4, retail margin debt had reached a record 37.74 trillion won. In simple terms, many retail investors had borrowed money from brokers to buy stocks.
When semiconductor stocks fell, portfolio values dropped quickly. Some accounts likely fell below the minimum level required by brokers. When that happens, brokers can automatically sell shares to reduce risk. This forced selling can push prices down even further. So, the sell-off is no longer just about sentiment. It may be mechanical.
3. Spillover into Japan: The pressure did not stop in South Korea. Some large funds losing money in Korean tech likely had to raise cash quickly. To do that, they may have sold profitable positions in other markets, including Japanese stocks.
The yen carry trade added another layer of pressure. This is a strategy where investors borrow cheaply in yen and invest that money in higher-return assets elsewhere. When markets fall sharply, investors often unwind these trades to reduce risk.
That selling likely spilled into Japanese equities, which is why the Nikkei’s fall looked broader than a direct semiconductor hit would explain.
Is the AI Stock Rally Breaking or Just Repricing?
This is the question that matters, and it's harder to answer than Monday morning Twitter would suggest.
| Index / Market | Trailing P/E | 10-Year Average P/E |
| KOSPI / South Korea | 17.91x | 10.30x |
| Nikkei 225 / Japan | 18.42x | 14.45x |
| TAIEX / Taiwan | 23.63x | 15.23x |
Source: Sources: World PE Ratio South Korea, World PE Ratio Japan, World PE Ratio Taiwan
KOSPI's 2026 rally is now being compared to the Nasdaq 100's 102% surge in 1999, just before the dotcom crash. That's a serious reference. But there's a material difference: the companies behind this rally are not priced like 1999 internet names. Samsung still trades at about six times its forward earnings, and SK Hynix at 5.3 times, a fraction of Nvidia's multiple.
Peter Kim of KB Securities told CNBC that the key risk that ends semiconductor upcycles, overcapacity, is "at least a couple of years" away from materializing. His view: today is a deleveraging event, not a structural break.
The counter-case is harder to ignore. Since May, foreign investors have net sold approximately $22 billion in South Korean stocks. And a Raymond James analyst recently warned that DRAM and NAND prices could peak around mid-2026, earlier than expected. That is a pricing risk on top of an already complicated picture.
Neither camp is obviously right today. The honest read is that the answer depends heavily on what comes next.
What Investors Should Watch After Market Crash
Goldman Sachs economists wrote that rate hikes "remain unlikely despite the strong jobs print," though many analysts agree that rate cuts aren't coming anytime soon either. Capital Economics' Stephen Brown took a more pointed view: the May jobs report "should further reduce concern among the FOMC about downside risks to the labor market, making it even harder for the Fed to try to look through elevated rates," and that the Fed will likely "enact a couple of insurance hikes later this year."
BTIG analyst Jonathan Krinsky had flagged two weeks ago that KOSPI was at risk of a "swift downside reversal," specifically pointing to the concentration risk of the index relying on just Samsung and SK Hynix. That warning proved accurate.
What to watch next: The next major test is the US Consumer Price Index for May 2026, scheduled for June 10. A softer inflation print would ease pressure on long-duration AI valuations, while another rate shock would test whether Korea's circuit breaker halt was only the first forced exit.
Samsung at 6x forward earnings is not a bubbly valuation. For investors who have a genuine 3-5 year view on AI infrastructure, and accept that HBM memory chips are central to that buildout, the fundamental case exists. But buying into a market being held down by forced margin selling, an unresolved geopolitical escalation, and a Fed policy decision still pending in June is genuinely uncertain. Waiting for the CPI print on June 10, and for some clarity on whether Iran's ceasefire holds, is a reasonable approach. Acting before that clarity arrives means absorbing risk that hasn't been fully priced yet.
This looks less like a broken market and more like an overheated one being forced to reprice after several negative triggers landed together.