According to a CNA report (carried by cna.com.tw and republished by news.cts.com.tw), US chip stocks rebounded on July 21, 2026, lifting the Dow 0.74%, the S&P 500 0.89%, the Nasdaq 1.29%, and the Philadelphia Semiconductor Index 5.21%. Memory makers SK Hynix and Micron led with gains of 13.75% and 12.17%, while Intel, AMD, and TSMC's ADR also advanced.
How did major US indices perform on July 21?
US equities broke out of a recent slump on July 21, 2026, with chip stocks driving the advance. According to CNA (cna.com.tw), "US stocks rose on July 21, boosted by a rebound in chip stocks, with the Dow Jones Industrial Average and S&P 500 gaining 0.74% and 0.89% respectively" (E1). The same report noted that the Nasdaq and the Philadelphia Semiconductor Index (SOX) — both of which had been under pressure from capital rotation and concerns over stretched AI valuations — "stopped falling and rebounded, rising 1.29% and 5.21%" (E2). The identical figures were also carried by CTS (news.cts.com.tw) in its republication of the CNA wire (E10), confirming the same set of index moves across both outlets.
Memory chipmakers SK Hynix and Micron post double-digit gains
The standout movers of the session were the two memory chipmakers. Per CNA, "memory giants SK Hynix's American Depositary Receipt (ADR) and Micron shook off their recent slump, surging 13.75% and 12.17% respectively" (E3), a figure repeated verbatim in the CTS republication (E11). Both stocks posted double-digit percentage gains, well above the single-digit moves seen across the broader chip complex that day.
How did logic chipmakers Intel and AMD trade?
Logic chipmakers also participated in the rally, though with smaller gains than the memory names. CNA reported that "chip stocks Intel and AMD, spurred by favorable news, gained 8.64% and 8.11%" respectively (E4). Both moves were in high-single-digit territory, trailing the double-digit advances posted by SK Hynix and Micron on the same day.
How did TSMC's ADR perform?
TSMC's (台積電) US-listed ADR also rose on July 21. CNA reported that "TSMC's ADR rose 5.55%, extending gains in after-hours trading" (E5), a figure matched in the CTS republication of the same wire report (E12). At 5.55%, TSMC's gain sat between the high-single-digit moves of Intel and AMD and the double-digit gains posted by the memory makers.
Which chip-linked companies report earnings this week?
CNA flagged three companies due to report results in the days following the rally: "Alphabet, IBM, and Tesla are set to report earnings this week, with the market watching how AI investment is translating into profit amid international competition, as well as second-half business outlooks" (E6). No specific figures for these upcoming reports were included in the source.
How are Chinese AI model developments and US tech rivalry factoring into sentiment?
Developments in China's AI sector were also cited as a market focus. CNA reported that Chinese startup Moonshot AI "recently unveiled its Kimi K3 AI model and plans to seek funding through a Hong Kong listing, which remains a focus for the market" (E7). Separately, CNA cited the Wall Street Journal reporting that executives at OpenAI and Anthropic — both preparing for IPOs — "believe that the rise of low-cost AI, particularly large new models from Chinese developers, will usher in a dystopian future, and that a lack of regulation will create safety risks" (E8). CNA also noted a competing interpretation: "some analysts who have studied the AI industry believe these comments are merely aimed at eliminating competition" ahead of the two companies' planned listings (E9).
| Stock / Index | Move on July 21, 2026 |
|---|
| Dow Jones Industrial Average | +0.74% |
| S&P 500 | +0.89% |
| Nasdaq | +1.29% |
| Philadelphia Semiconductor Index (SOX) | +5.21% |
| SK Hynix (ADR) | +13.75% |
| Micron | +12.17% |
| Intel | +8.64% |
| AMD | +8.11% |
| TSMC (ADR) | +5.55% |
What this means
Across the four benchmarks cited by CNA, the SOX's 5.21% gain far outpaced the 0.74%–1.29% moves in the Dow, S&P 500, and Nasdaq, underscoring that the rebound was concentrated in chip stocks rather than the broader market. Within the chip complex itself, the gains were uneven: SK Hynix and Micron's double-digit moves (13.75% and 12.17%) sat well above the high-single-digit gains posted by Intel, AMD, and TSMC's ADR (8.64%, 8.11%, and 5.55%), pointing to memory names as the session's clear standout. That rally came as the market also digested conflicting signals on China's AI progress — Moonshot AI's Kimi K3 unveiling and Hong Kong listing plans on one hand, and dueling interpretations of OpenAI and Anthropic executives' warnings about low-cost Chinese AI models on the other — with Alphabet, IBM, and Tesla's earnings this week set to offer the next test of how AI investment is translating into results.