Shares of Samsung Electronics surged 26.81% on Friday, climbing 55,500 won to close at 262,500 won, effectively hitting the exchange’s daily limit for individual stock price movements as South Korea’s benchmark KOSPI index posted the largest single-day rally in its history.

The KOSPI closed up 17.91% at 6,595.45, marking a record in both point and percentage terms, according to the Korea Herald, as chip stocks across the board rebounded sharply from a punishing weeklong selloff. Rival chipmaker SK Hynix climbed 29.95% during the same session, according to TradingKey, as both of South Korea’s dominant memory chip producers effectively erased much of the ground they had lost during three brutal preceding trading sessions.

Friday’s rally traced its origins directly to a powerful overnight session on Wall Street. Microsoft’s shares soared 15.5% Thursday for the company’s best single-day performance in nearly 18 years, according to the Associated Press, after the technology giant reported that its Azure cloud computing division grew 43% during the quarter, easing broader investor concerns about the sustainability of massive capital spending on artificial intelligence infrastructure. Amazon and Meta Platforms also posted upbeat results that reinforced expectations that AI-related spending remains robust, according to CNBC, sending shockwaves of optimism through Asian technology markets overnight.

Samsung’s own earnings had already reflected the underlying strength driving the rally, even before Friday’s dramatic share price move. The company’s semiconductor division reported operating income of 89.5 trillion won, beating the 88.13 trillion won analysts had expected, with robust artificial intelligence demand continuing to drive growth across Samsung’s memory chip business. The results confirmed that DRAM and NAND flash memory sales remained at all-time highs during the quarter, providing powerful third-party validation that the artificial intelligence-driven memory supercycle remains firmly intact even amid the recent bout of extreme volatility across the sector.

Friday’s rebound followed a brutal stretch for Korean equities. The KOSPI had plummeted more than 17% over the three trading sessions preceding Friday, driven by investor concerns about a potential bubble in artificial intelligence valuations and intensifying competition from Chinese chipmaking rivals, according to the Associated Press. At one point during that selloff, the index had fallen roughly 40% from its June peak, wiping out nearly $2 trillion in market value, according to reporting from the Private Banker.

Foreign investors were the driving force behind Friday’s historic rebound, posting net purchases of 7.25 trillion won, or roughly $5.06 billion, on the KOSPI, according to the Korea Herald. That marked a second consecutive day of net foreign buying, following four straight sessions of net selling that had preceded Thursday. Institutional investors, who began Friday’s session as net sellers, reversed course around midday and ended the day with net purchases of 1.15 trillion won.

Additional factors beyond the Microsoft-driven rally appeared to reinforce Friday’s gains for Samsung and SK Hynix alike. SK Group Chairman Chey Tae-won disclosed personal purchases of SK Hynix shares during the recent selloff, a move that bolstered broader investor confidence in South Korea’s memory chip sector, according to CNBC. New cash-deposit requirements for investors using leveraged exchange-traded funds also took effect July 31, a regulatory change some analysts said may have contributed to a broader repositioning among traders active in that corner of the market, while short-covering and mechanical rebalancing tied to leveraged ETFs were also cited as factors amplifying the scale of Friday’s move.

Despite the historic single-day gain, market analysts urged caution about reading too much into the rebound. Speaking to CNBC, one analyst identified only as Jung said foreign investors appeared to be the primary force behind Friday’s rally, but cautioned against assuming the gains signal a durable trend reversal. “I would not expect gains of this magnitude to continue,” Jung said, adding that asset prices had become “completely disconnected” from underlying fundamentals during the recent volatility.

Even after Friday’s rally, the KOSPI remained well below its levels from earlier in the year. The index recorded its worst monthly performance since 1997, dropping 22.19% over the course of July, according to TradingKey, underscoring that Friday’s rebound, while historic in scale, only partially offset the scale of losses the index had absorbed over the preceding weeks.

South Korean authorities also announced new measures Friday aimed at supporting the country’s technology and artificial intelligence sector more broadly. The government said it would inject a minimum of 20 trillion won, or approximately $13.9 billion, into the Korea Investment Corporation for strategic investments in artificial intelligence, data centers and broader infrastructure, according to the Private Banker, marking the first time the sovereign wealth fund’s mandate has been expanded to include domestic assets.

With Samsung shares having now hit the exchange’s daily trading limit and the broader KOSPI having posted its largest single-day gain on record, investors are likely to watch closely in the sessions ahead for signs of whether Friday’s rebound marks a genuine stabilization in sentiment toward AI-linked technology stocks or another dramatic swing within a period of extraordinary volatility that has gripped South Korea’s chip-heavy equity market throughout the second half of July.