South Korean investors have aggressively liquidated individual U.S. semiconductor positions since the start of September, while concentrating capital into a leveraged ETF that tracks triple the daily return of the semiconductor index. The pattern reflects a strategic diversification play: avoiding peak-valuation risk in single names while maximizing short-term upside exposure to the sector as a whole.
According to data from the Korea Securities Depository’s securities information portal released on September 6, South Korean retail investors net sold more than $100 million (approximately 140 billion won) worth of Micron over the four trading days from September 1 through September 4. During the same period, they offloaded $68.61 million of SanDisk, the NAND flash memory maker, and $49.37 million of Marvell Technology, which produces networking and communications semiconductors for data centers.
Nvidia, the world’s most valuable company by market capitalization, also recorded net selling of $15.56 million, while SK Hynix ADRs saw net outflows of $46.16 million (approximately 62.2 billion won). SK Hynix ADRs had attracted net buying of $810.97 million (approximately 1.0938 trillion won) from their New York listing in July through the end of August, making this the first clear profit-taking signal since the ADR debut.
In stark contrast to the individual stock selling, SOXL — the Direxion Daily Semiconductor Bull 3X Shares ETF — attracted inflows of $430.95 million. SOXL tracks triple the daily return of the PHLX Semiconductor Index, and South Korean retail investors held an estimated $5.23172 billion in the product as of the end of August. After selling $752.44 million worth over two sessions on August 28 and 31, they resumed accumulation in September.
This portfolio reshuffling reflects the simultaneous pull of “peak-out” concerns — that semiconductor earnings have crested — and long-term growth expectations. The strategy appears to be: lock in short-term gains on individual names, but maintain upside beta to the broader semiconductor sector as long as the AI infrastructure investment cycle persists.
Indeed, the U.S. memory semiconductor market remains in a state of tight supply-demand conditions. On September 5, Micron surged 6.1%, SanDisk jumped 11.9%, and SK Hynix climbed 8.1%, while Western Digital rose approximately 6%. The Roundhill Memory ETF gained 6.6%, indicating broad-based buying across the sector.
Micron’s cutting-edge memory production capacity is reportedly fully booked through the end of 2026. Dell’s $95 billion (approximately 128.4 trillion won) AI server order backlog is cited as evidence that major technology companies are effectively absorbing all producible memory wafers. According to Barron’s, global DRAM revenue surged 57% quarter-over-quarter in Q2, while NAND revenue jumped 70%, with Micron expanding its DRAM market share to 24%.
Wall Street price target upgrades continue to roll in. UBS analyst Timothy Arcuri raised his HBM average selling price (ASP) growth forecast from 67% to 79%. Addressing concerns that memory content per AI accelerator could decline, he countered that if Nvidia supplies more accelerators, total HBM demand could still expand despite reduced memory per individual chip.
Lynx Equity projected that the memory supply shortage will persist for years, setting a Micron price target of $1,325 (approximately 1.8 million won) and a SanDisk target of $2,450 (approximately 3.3 million won). Bernstein maintained an Outperform rating on SanDisk and dramatically raised its price target from $1,700 (approximately 2.3 million won) at the end of June to $3,000 (approximately 4.1 million won), citing long-term supply agreements that include price protection clauses and prepaid customer commitments.
Mizuho characterized memory as the “critical bottleneck” in the semiconductor supply chain and maintained an Outperform rating on Micron. Nvidia’s disclosed $279 billion (approximately 377 trillion won) in supply and production capacity-related obligations is largely tied to memory components and manufacturing capacity, underscoring how central memory access has become to AI infrastructure buildouts.
China-related risk, however, remains a wildcard. Chinese chipmaker YMTC’s global NAND market share rose from 9% a year ago to 14% in Q2, while SanDisk’s share fell from 13% to 11%. Should the market flip to oversupply, downward price pressure could intensify.
Beyond SOXL, South Korean retail investors also added $94.92 million to SGOV (iShares 0-3 Month Treasury Bond ETF), a U.S. short-term Treasury ETF with maturities under three months, increasing their cash-equivalent allocation. Quantum computing company IonQ ranked third in net buying at $47.28 million, followed by JEPQ (JPMorgan Nasdaq Equity Premium Income ETF), a Nasdaq-based monthly distribution ETF, at $39.88 million, and U.S. pharmaceutical company Merck at $36.65 million.
The overall trading pattern can be summarized as a diversified strategy combining volatility management with return-seeking behavior. Investors are reducing valuation exposure in individual names while maintaining upside participation through leveraged ETFs, and bolstering portfolio cash buffers with short-term Treasury ETFs. The moves reflect simultaneous profit-taking impulses following sharp short-term rallies, even as memory sector fundamentals remain robust.