Samsung fell 7.52% to 243,000 won and SK Hynix dropped 6.90% to 1,600,000 won in Monday's completed Seoul session, according to TradingKey data published August 3. The KOSPI closed 4.86% lower at 6,274.74, one trading day after posting the largest single-day gain in its history, while Japan's Nikkei slipped a comparatively mild 1.12%. The KOSPI is South Korea's benchmark stock index, and the two memory chipmakers are its heaviest weights, which means the memory trade now swings the entire Korean market in both directions.
Memory trade snapshot, August 3, 2026:
|
Name
|
Friday move
|
Monday move
|
The stake
|
|
Samsung
|
+26.81% (Sedaily)
|
-7.52%
|
The largest DRAM maker in a disputed pricing upcycle
|
|
SK Hynix
|
+29.95%, the daily upper limit (KED)
|
-6.90%
|
The HBM leader at the center of the whiplash
|
|
Kioxia
|
No verified Friday print
|
+6.37%
|
The NAND name that bucked the selloff
|
|
Micron
|
-5.90%
|
No US session until after publish
|
First US read on Seoul's reversal at the open
|
|
SanDisk
|
-5.09%
|
No US session until after publish
|
Wednesday's after-close print decides the next leg
|
|
Western Digital
|
+2.15%
|
No US session until after publish
|
Reports the same Wednesday night as SanDisk
|
Friday's tape said the memory bottom was in, and Monday's tape called it a squeeze. SanDisk's Wednesday report is the first hard number that can settle the argument, and the options market is already priced for a violent answer either way.
A Record Friday, a Brutal Monday, and What Changed in Between
July was the worst month for the KOSPI since October 2008, a 22.2% decline that TradingKey attributes to the unwind of Korea's retail-leveraged AI chip trade. Then Friday delivered the snapback, with the index up 17.91% in a single session. Samsung closed that day at 262,500 won by Sedaily's count, and SK Hynix finished pinned at the exchange's daily ceiling per the Korea Economic Daily.
That ceiling detail matters more than it looks. Korea's main board caps single-stock daily moves at 30%, a circuit breaker that works like a dam. Buying pressure that cannot execute on Friday spills into Monday's open, and so does the profit-taking from anyone who caught the surge. When a stock reopens after a limit-up close, the first session mostly clears a backlog of orders that never got to execute. Our KOSPI 2026 breakdown covers how the index got this reflexive, and our Samsung trader positioning guide tracks how crowded the name was before July broke it.
Kioxia is the tell that Monday was not simple risk-off. The Tokyo-listed NAND maker rose 6.37% while everything DRAM-flavored in Seoul bled, which reads like money rotating toward the flash-memory story SanDisk will report on Wednesday.
Seoul Brokerages Still Have Targets Near Double the Price
Sedaily reported on August 3 that the average brokerage price target sits at 514,545 won for Samsung and 3,371,538 won for SK Hynix. Measure those against Monday's closes and the gap is roughly two to one on both names, even after Friday's historic surge. A gap that wide reads one of two ways. Either the sell side sees an earnings cycle the tape has not priced, or the analysts have not caught up with a market that repriced Korean risk in a single week.
The bull anchor under those targets is concrete. UBS analyst Nicolas Gaudois raised the bank's third-quarter DDR contract-price forecast on Friday to 32% quarter-over-quarter growth, up from a prior 17%, per coverage syndicated through Yahoo and Benzinga on July 31. Contract prices are what Samsung and SK Hynix actually bill customers, so a near-doubling of the growth assumption feeds straight into the earnings models behind those won-denominated targets. Our SK Hynix price analysis and long-term HBM outlook maps how earlier stages of this pricing cycle translated into earnings, and our profile of SK Hynix CEO Kwak Noh-jung explains the HBM bet that made the company the sector's bellwether.
And the bear reading deserves equal space. Analysts who kept targets at double the price through July's 22.2% collapse were wrong for a full month before Friday bailed them out. Targets are a lagging opinion, and the tape spent most of the summer disagreeing with them.
The US Memory Names Already Ran This Script on Friday
Friday, July 31 was the last completed US session, and it previewed Seoul's Monday almost beat for beat. Micron opened sharply higher and sold off all day to close down 5.90%, while SanDisk gave back 5.09% after its $1,383.69 opening print fully reversed. Western Digital held onto a 2.15% gain, the only one of the three to keep anything. Our August 2 piece on the memory whipsaw walked through that Thursday rebound and Friday fade in detail, and Monday's Korean session repeated the shape one time zone earlier.
The pattern is the same on both continents. Memory stocks are gapping on supply-cycle headlines and then bleeding once the opening queue clears, which is what happens when a trade is driven by positioning rather than conviction. The cost side of the story is not in dispute, since Apple guided its margins down on memory prices Tim Cook called a "100-year flood," a warning our August 2 Apple coverage unpacked. What the market cannot settle is who captures that repricing, and the Micron versus SK Hynix comparison shows how differently the two DRAM leaders are positioned for it.
Server builders sit downstream of the same costs, and Super Micro's 2.42% Friday gain shows the market still treating assemblers as pass-through names while the component makers absorb the volatility. US futures trade before the bell today, so any premarket prints on Micron or SanDisk are drift, not a session. The first real American vote on Seoul's reversal comes at the open, after this article publishes.
SanDisk Carries the Biggest Implied Move of the Week
SanDisk reports Wednesday, August 5 after the US close, and options are pricing a 17.47% swing, the largest implied move of any company worth more than $50 billion reporting this week per Benzinga's August 2 screen. An implied move is the size of the earnings-night swing option prices currently pay for, in either direction, so a straddle that size on a stock that closed Friday at $1,214.83 means traders are paying for roughly $200 of movement per share before Thursday's open.
The stock has earned that pricing. SanDisk is up 423.2% year to date on the NAND shortage story, and a name that quadruples into a print tends to move violently on any deviation from the script. Sell-side EPS estimates for the quarter differ meaningfully by provider, so the cleaner anchors are the company's own revenue guidance of $7.75 billion to $8.25 billion and the options market's expectation. Western Digital reports the same Wednesday night carrying a 13.39% implied move of its own, which turns the night into a two-company reading on flash memory pricing. Listing details and the earnings calendar sit on SanDisk's Nasdaq page.
Kioxia's Monday bid suggests some traders are already front-running a strong NAND answer, which quietly raises the bar for what counts as a positive surprise. A strong guide validates the pricing math holding up those doubled brokerage targets, and a weak one tells the market Friday's record session was positioning, with nothing underneath it.
What Decides Which Session Was Telling the Truth
The honest framing is that Friday and Monday cannot both be right. A record index day says the memory cycle turned, and a near-5% giveback one session later says the move was mechanical. Three checkpoints resolve it this week. First, today's US open shows what American money does with Seoul's reversal after a weekend to think. Second, SanDisk and Western Digital report Wednesday night with pricing power data no analyst forecast can override. Third, Seoul's reaction Thursday morning shows how Samsung and SK Hynix trade once hard NAND numbers replace momentum.
The macro backdrop moved overnight as well, with oil crashing on Iran de-escalation headlines and September rate expectations shifting with it, a story today's oil and Iran macro piece covers in full. Rate-sensitive growth names like the memory complex inherit that volatility on top of their own.
Frequently Asked Questions
Why did Samsung stock drop today?
Samsung dropped about 7.5% in Monday's Seoul session on August 3, 2026, as traders took profits from the historic rebound that ended the prior week. Korean price-limit mechanics queue unexecuted orders into the next open, so part of Monday's selling was Friday's business finally clearing. Even after the drop, the stock held onto most of Friday's rebound.
When does SanDisk report earnings?
SanDisk reports quarterly results on Wednesday, August 5, 2026, after the US market close, with Western Digital releasing its own numbers the same evening. The print reaches Asian trading hours Thursday morning, which makes Samsung and SK Hynix the first large memory names to trade on it. That timing turns one American earnings call into a global memory-sector event.
What is an implied move in earnings?
An implied move is the percentage swing that options prices expect from a stock around a known event, calculated from the cost of an at-the-money straddle expiring immediately after the event. It measures the cost of insurance around the date and says nothing about direction. A 17.47% implied move means options buyers are paying for a swing of that size up or down.
Why is the KOSPI so volatile right now?
The index is dominated by its two memory chipmakers, so any repricing of the global DRAM and NAND cycle hits Korea harder than any other major market. Heavy retail leverage in Korean chip names amplifies moves in both directions, which is how a record monthly loss and a record daily gain landed within days of each other. Until memory pricing settles, the KOSPI will keep trading like a single-sector bet.
Bottom Line
If SanDisk's Wednesday guide confirms the NAND pricing cycle, the target gap in Seoul closes upward and Monday's 7% drops in Samsung and SK Hynix start to look like entries. If the guide disappoints, Friday's record session goes down as a short squeeze inside a bear market, and the doubled brokerage targets become the next thing to fall. The memory trade has produced a record monthly loss, a record daily gain, and a 7% reversal inside five trading days, and by Thursday morning Seoul time it will finally have hard earnings data to trade on.
This article is for informational purposes only and does not constitute financial or investment advice. Cryptocurrency trading involves substantial risk. Always conduct your own research before making trading decisions.
