On August 6 ET (early morning August 7 Beijing time), the three major US stock indexes once again showed divergent trends. At the close, the Nasdaq Composite rose 0.35% against the trend, driven by heavyweight tech stocks such as Apple and Nvidia; the S&P 500 hovered around the flatline; the Dow Jones Industrial Average fell more than 200 points, or about 0.5%, dragged down by traditional cyclical stocks such as Caterpillar. AI hardware stocks that had been collectively pressured during the session staged a "big reversal," with the Philadelphia Semiconductor Index erasing early losses and turning higher, led by TSMC, AMD, Micron Technology and others.
The market surface seemed calm, but underneath there were undercurrents: the Trump administration's "100% chip tariff" bombshell, the memory-chip duopoly's "beat yet slump" paradox, SpaceX's largest-ever US stock lockup expiration, plus renewed tensions over the Strait of Hormuz in the Middle East. Multiple variables intertwined, leaving investors both excited and wary.
Trump's 100% chip tariff lands: "Made in America" exemption becomes key variable
On August 6 local time, US President Trump said the US would impose about 100% import tariffs on chips and semiconductors, but promised that companies manufacturing in the US would be exempt. The news initially pressured the semiconductor sector, which quickly turned stronger. TSMC rose nearly 6% intraday, AMD rose 6%, Micron gained over 3%, and Nvidia rose nearly 2%, hitting a fresh record intraday.
The market's "first scare, then cheer" hinged on the tariff exemption logic. Trump made clear that "if you make it in America, there will be no charge," which Wall Street read as a carrot-and-stick strategy to bring industry back onshore. Shortly after, Apple CEO Tim Cook announced in the White House Oval Office that the company would add $100 billion in US investment over the next four years. Combined with the previously pledged $500 billion, total investment would reach $600 billion, and Apple would advance its "Made in America" plan. Apple shares jumped about 5% that day, pushing its market value back toward the $5 trillion mark.
Analysts noted that for giants like Apple with deep domestic capacity, this round of tariff threats was "more bark than bite." The real impact may be felt more through cost transmission in intermediate segments such as semiconductor equipment and memory modules. For Asian supply chains, the pace and exemption details of tariff implementation remain the biggest source of uncertainty in the coming months.
Memory-chip duopoly earnings: why did "beating expectations" bring a sharp sell-off?
The most intriguing part of this session was the "expectation paradox" of the two memory-chip giants. After the close on August 5, Western Digital and SanDisk reported fiscal Q4 2026 results: Western Digital revenue of $3.75 billion, up 44% year over year, beating the $3.692 billion market consensus; adjusted EPS of $3.56 also beat the analysts' $3.31 forecast. SanDisk likewise delivered a beat and announced a $14 billion large-scale buyback plan.
Yet the impressive report did not win applause — Western Digital fell more than 11% after hours, and SanDisk fell more than 7%. During the August 6 session, SanDisk continued lower by over 5%, and Western Digital fell as much as 10%. The cause pointed to guidance: SanDisk's revenue guidance for the next quarter ($10.3 billion to $10.8 billion) had a midpoint below analysts' $10.82 billion estimate. Western Digital's guidance was broadly in line, but the market had already priced in more.
This reflects the "position anxiety" of the AI storage super-cycle. Over the past 12 months, SanDisk shares had surged roughly 3,000%, and Western Digital had soared more than 530%, pushing valuations and expectations to extremes. JJ Kinahan, Cboe's head of retail business development and alternative investments, noted that better-than-expected profit and revenue paired with soft guidance do not always lift the stock, and some funds took the opportunity to lock in gains.
From an industry logic perspective, AI training and inference still point to explosive demand for HBM and enterprise SSDs, but concerns about a cyclical peak are rising in parallel. If earnings guidance cannot keep being revised upward, valuation-de-rating risk will first materialize in the best-performing names. This quarter offers a lesson for AI-chain investors: the "sell the fact" script often arrives faster than the "beat" itself.
SpaceX's $100 billion lockup: the biggest supply test in US stock history
Another disturbance came from SpaceX. On Thursday ET, roughly 912 million locked-up SpaceX shares were released. Based on the August 4 close of $125.33, that corresponds to a market value of about $114 billion, roughly 1.4 times the company's current float, setting a record for the largest lockup expiration in US capital-markets history. Before that, SpaceX shares had been highly volatile. Its first post-listing earnings report showed narrowing AI-related losses but higher-than-expected spending, and the company saw about $225 billion in market value evaporate in a single day on Wednesday.
Industry analysts said that as lockup shares are gradually absorbed, SpaceX's valuation will shift from "story-driven" to "fundamental verification." The commercialization progress of satellite internet and Starship launch business will become a core variable for the stock. For Asian investors keen on new US listings and growth stocks, position management in such high-volatility names requires extra caution.
Middle East turbulence and nonfarm payrolls: volatility may be the norm
On the macro front, geopolitical risk is resurfacing. On one hand, reports that Iran and Oman are close to reaching a deal to reopen the Strait of Hormuz briefly soothed market sentiment. On the other, the Iranian parliament is reviewing a draft law to tighten controls on transit rules for the strait and the Persian Gulf, including restricting passage of ships linked to the US and Israel. The news sent international oil prices sharply higher intraday, and the Dow fell. Deutsche Bank strategist Jim Reid cautioned that markets have repeatedly seen "false dawns" as conflicts evolve, and details such as the final form of a deal and toll ownership remain unresolved.
Stock-specific noise was also abundant: Salesforce fell 3.8% on a leadership reshuffle, and AppLovin plunged 19% on mixed results. On the macro-data front, the US July nonfarm payrolls report is due on the evening of August 7 Beijing time. It will be the first full employment report since the Fed held rates steady in July, and its strength will directly determine how the market prices the path to a September rate cut.
Three key points for the outlook
- After the tariff exemption details are finalized, re-pricing of semiconductor supply-chain cost restructuring and "Made in America" beneficiaries;
- As the memory cycle shifts from "volume and price rising together" to "expectation verification," be wary of valuation-de-rating risk in high-flying names;
- The SpaceX lockup window continues to release shares (more tranches on August 20, September, and October), with marginal changes in growth-stock supply pressure.
All in all, US stocks are in a phase where earnings realization, policy games, and lockup impacts overlap. The divergence among indexes is essentially the result of funds rotating between high and low positions within the AI main line and rebalancing between cyclicals and growth. Until the Fed's policy path becomes clearer, increased volatility may be the norm. Controlling positions, maintaining balanced allocation, and anchoring on earnings certainty remain the pragmatic choices to navigate the choppy period.
