From circuit breakers to a surge: Korea’s stock market flips to extremes in 24 hours—has semiconductor sentiment hit the bottom?
On the last trading day of July, the KOSPI index of South Korea once saw intraday gains reach 14.77%, setting the largest single-day gain in the index’s history. SK hynix surged 25% in a single day.
And just 48 hours earlier, the very same stock, in the same market, had just gone through panic selling and circuit breakers.
This is a textbook “V-shaped extreme reversal.”
1. From despair to greed—just one night is enough
Let’s review this week’s rhythm: on Tuesday, panic spread across the South Korean market, with SK hynix leading the decline. Sentiment spilled over into A-share sectors such as storage and computing power. In the Asia-Pacific technology theme, names broadly sold off.
At the time, the narrative was all “AI hardware cycle has topped” and “storage has entered a downward channel,” with ghost stories flying everywhere.
The turning point came on Wednesday night. U.S. storage plays such as Micron and SanDisk staged a violent rebound first, breaking the several-days-long pessimistic atmosphere. On Thursday’s early session, the South Korean market picked up the baton—short sellers covered positions, combined with sentiment repair—delivering this history-book-level surge.
2. Four real driving forces behind the rally
Many people ask: if Korea’s stock market is up 15% in one day, did something major happen?
Frankly, this rise wasn’t driven by fundamentals—it’s a classic “technical extreme repair”:
First, a short squeeze as shorts are forced to close. Large short-term short positions accumulated the day before were covered in bulk, in the absence of new negative news, naturally amplifying upside volatility.
Second, the leverage effect of high-weight storage stocks. SK hynix has an extremely high weight in the KOSPI. When it rose 25% in a day, the index was pulled straight up.
Third, a vacuum period after panic chips are cleared. After a streak of declines, panic selling had largely been washed out. With sell pressure depleted, marginal buyers’ pricing power was massively amplified—only a small amount of capital was needed to push the stock market higher.
Fourth, global technology fund reallocation. After a round of deep pullbacks, some left-side capital began reassessing the odds of the semiconductor sector and chose to rebuild positions at this point.
In one sentence: extreme oversold conditions plus short-covering plus sentiment repair equals a 14% surge in a single day.
3. For A-share semiconductors: sentiment catalysis isn’t the same as a trend reversal
This is the part that needs the most calm.
The transmission path of sentiment is clear: U.S. storage jumps, which drags South Korea’s KOSPI higher; global semiconductor risk appetite rebounds; on the A-share side, storage chips, HBM, and packaging/testing follow to capture the sentiment tailwind.
But there’s a key distinction here: sentiment repair is pulse-like, while trend reversals require fundamental confirmation. Currently, key variables such as spot storage prices and downstream AI capital expenditures have not undergone a sudden shift. This means the storage industry chain directly benefits the most from the overseas mirroring, with the strongest elasticity. Meanwhile, things like optical modules and servers are more indirectly affected; once sentiment ebbs, they can easily revert to their original rhythm. For A-shares, the stockpiles of trapped investors are dense from earlier periods—after a high opening, the strength of follow-through is the key variable determining whether the rally can continue.
4. Two possible scripts ahead
Script one is relatively optimistic: the Korean market trades in high-range consolidation all day without falling back. After A-shares open high, volume and follow-through cooperate strongly, producing a decent oversold-repair move. But even if it reaches that point, it can only be defined as a technical rebound—it cannot be treated as the start of a brand-new primary rally.
Script two is more cautious: the Korean market spikes then falls back, with gains shrinking significantly—good sentiment is effectively prepaid. A-shares are prone to a “high open, then weak close” style of profit-taking. In that case, only fundamentally solid leading companies at the top can carve out an independent trend; the rest will likely revert to their original form.
5. What to do from a strategy perspective
For those who already hold positions, use the rebound window to optimize position structure—not add and chase the rally. There are two core observation indicators: trading volume in the first half hour after the open, and how the sector differentiates internally.
For funds on the sidelines, I don’t recommend blindly chasing after news catalysts. A better strategy is to wait until the market shows separation and confirmation of stabilization before acting. At that time, prioritize leading names in industry chains whose performance can be verified. Try to avoid mid- and small-cap stocks driven purely by speculative themes.
Written at the end
In 24 hours, South Korea’s stock market completed the switch from “world’s end” to “epic celebration.” This injected a powerful short-term sentiment repair dose into the global semiconductor market, and A-share tech sectors will undoubtedly feel this wave of warm offshore winds.
But the essence of investing has never been guessing the peak of sentiment—it’s judging the anchor point of value. Whether this rally can turn from a rebound into a reversal will require continued validation of fundamental signals afterward, such as a turning point in storage prices and sustained verification of AI compute capital expenditure. Until then, staying clear-headed matters more than staying enthusiastic. #SK海力士单日暴涨25%
On the last trading day of July, the KOSPI index of South Korea once saw intraday gains reach 14.77%, setting the largest single-day gain in the index’s history. SK hynix surged 25% in a single day.
And just 48 hours earlier, the very same stock, in the same market, had just gone through panic selling and circuit breakers.
This is a textbook “V-shaped extreme reversal.”
1. From despair to greed—just one night is enough
Let’s review this week’s rhythm: on Tuesday, panic spread across the South Korean market, with SK hynix leading the decline. Sentiment spilled over into A-share sectors such as storage and computing power. In the Asia-Pacific technology theme, names broadly sold off.
At the time, the narrative was all “AI hardware cycle has topped” and “storage has entered a downward channel,” with ghost stories flying everywhere.
The turning point came on Wednesday night. U.S. storage plays such as Micron and SanDisk staged a violent rebound first, breaking the several-days-long pessimistic atmosphere. On Thursday’s early session, the South Korean market picked up the baton—short sellers covered positions, combined with sentiment repair—delivering this history-book-level surge.
2. Four real driving forces behind the rally
Many people ask: if Korea’s stock market is up 15% in one day, did something major happen?
Frankly, this rise wasn’t driven by fundamentals—it’s a classic “technical extreme repair”:
First, a short squeeze as shorts are forced to close. Large short-term short positions accumulated the day before were covered in bulk, in the absence of new negative news, naturally amplifying upside volatility.
Second, the leverage effect of high-weight storage stocks. SK hynix has an extremely high weight in the KOSPI. When it rose 25% in a day, the index was pulled straight up.
Third, a vacuum period after panic chips are cleared. After a streak of declines, panic selling had largely been washed out. With sell pressure depleted, marginal buyers’ pricing power was massively amplified—only a small amount of capital was needed to push the stock market higher.
Fourth, global technology fund reallocation. After a round of deep pullbacks, some left-side capital began reassessing the odds of the semiconductor sector and chose to rebuild positions at this point.
In one sentence: extreme oversold conditions plus short-covering plus sentiment repair equals a 14% surge in a single day.
3. For A-share semiconductors: sentiment catalysis isn’t the same as a trend reversal
This is the part that needs the most calm.
The transmission path of sentiment is clear: U.S. storage jumps, which drags South Korea’s KOSPI higher; global semiconductor risk appetite rebounds; on the A-share side, storage chips, HBM, and packaging/testing follow to capture the sentiment tailwind.
But there’s a key distinction here: sentiment repair is pulse-like, while trend reversals require fundamental confirmation. Currently, key variables such as spot storage prices and downstream AI capital expenditures have not undergone a sudden shift. This means the storage industry chain directly benefits the most from the overseas mirroring, with the strongest elasticity. Meanwhile, things like optical modules and servers are more indirectly affected; once sentiment ebbs, they can easily revert to their original rhythm. For A-shares, the stockpiles of trapped investors are dense from earlier periods—after a high opening, the strength of follow-through is the key variable determining whether the rally can continue.
4. Two possible scripts ahead
Script one is relatively optimistic: the Korean market trades in high-range consolidation all day without falling back. After A-shares open high, volume and follow-through cooperate strongly, producing a decent oversold-repair move. But even if it reaches that point, it can only be defined as a technical rebound—it cannot be treated as the start of a brand-new primary rally.
Script two is more cautious: the Korean market spikes then falls back, with gains shrinking significantly—good sentiment is effectively prepaid. A-shares are prone to a “high open, then weak close” style of profit-taking. In that case, only fundamentally solid leading companies at the top can carve out an independent trend; the rest will likely revert to their original form.
5. What to do from a strategy perspective
For those who already hold positions, use the rebound window to optimize position structure—not add and chase the rally. There are two core observation indicators: trading volume in the first half hour after the open, and how the sector differentiates internally.
For funds on the sidelines, I don’t recommend blindly chasing after news catalysts. A better strategy is to wait until the market shows separation and confirmation of stabilization before acting. At that time, prioritize leading names in industry chains whose performance can be verified. Try to avoid mid- and small-cap stocks driven purely by speculative themes.
Written at the end
In 24 hours, South Korea’s stock market completed the switch from “world’s end” to “epic celebration.” This injected a powerful short-term sentiment repair dose into the global semiconductor market, and A-share tech sectors will undoubtedly feel this wave of warm offshore winds.
But the essence of investing has never been guessing the peak of sentiment—it’s judging the anchor point of value. Whether this rally can turn from a rebound into a reversal will require continued validation of fundamental signals afterward, such as a turning point in storage prices and sustained verification of AI compute capital expenditure. Until then, staying clear-headed matters more than staying enthusiastic. #SK海力士单日暴涨25%
