A $1 trillion selloff

Semiconductor stocks have abruptly fallen, with the world's most valuable chip stocks shedding over $1 trillion in market value. Nvidia led the decline, losing $238 billion since the previous Friday's close, while SK Hynix, Samsung Electronics, Micron, AMD and TSMC each lost more than $100 billion. Alphabet, meanwhile, raised its 2026 capital expenditure forecast in the same week.1 The fall appears to be driven by a shift in investor sentiment rather than by any deterioration in demand.

Semiconductor stocks have long been viewed as a barometer of the global economy. From smartphones to artificial intelligence and electric vehicles, almost every industry today depends on semiconductors. So when investors rapidly sell chip companies, the question extends beyond technology: what changed?

The more interesting question is not why chip companies remain profitable today, but why investors suddenly believe their future will be less profitable than they did only weeks ago. Like any economic question, many factors could have contributed, and it is difficult to isolate a single cause. Rather than one trigger, a combination of forces has driven the decline.

Great Expectations

Semiconductor stocks rose enormously over the past few years, with Taiwan becoming globally renowned as the epicentre of advanced chip manufacturing. Much of that growth was driven by expectations that AI would generate years of exceptional earnings rather than by present profits. Chip shares had consistently outperformed the broader market, so even small disappointments triggered heavy selling. Because markets price future profits rather than current ones, investors take fright when rapid expansion gives way to cooling demand.

The scale of the preceding rally matters. The Philadelphia Semiconductor Index, known as the SOX, tracks the thirty largest US-traded companies in the chip sector. It had risen 92% over the twelve months to late July, even after falling nearly 20% across the preceding month.1 A drop of that size following a gain of that size reads very differently from one arriving out of nowhere.

The more interesting question is not why chip companies remain profitable today, but why investors suddenly believe their future will be less profitable than they did only weeks ago.

Is this the cycle turning?

Historically, semiconductor stocks are highly volatile, moving through alternating periods of oversupply and undersupply. A leading-edge fabrication plant costs more than $20 billion and takes three to four years from investment decision to first production wafer, and the lithography systems inside it carry lead times of twelve to twenty-four months.2 Supply therefore always responds late to shifts in real demand.

This lag produces one of the industry's defining characteristics: the cobweb cycle. Demand exceeding supply pushes average selling prices higher. Companies then invest heavily to build new capacity. By the time that capacity arrives, demand has already been satisfied, and the resulting excess inventory produces a downturn in which profit margins are squeezed. Only once that inventory clears do prices stabilise. Matching supply to demand for any sustained period is extremely difficult.

On that description, however, the current episode does not look like a cobweb downturn. A classic inventory correction shows up as falling selling prices and swollen stockpiles, with margins compressed by capacity that arrived too late to be needed. What the market has repriced instead is the value of earnings that are still growing. The distinction matters, because an inventory glut clears on a reasonably predictable schedule, whereas a change in what investors are willing to pay for future profits need not.

When politics moves markets

Beyond market fundamentals, geopolitics has become one of the semiconductor industry's greatest sources of uncertainty. In late July, The Information reported that a Chinese company had begun manufacturing an immersion deep ultraviolet lithography machine, a market ASML has long dominated. ASML shares fell on the news, which was read as evidence that Beijing's drive to build a self-sufficient chip supply chain, accelerated by years of export controls, is beginning to succeed.3

July was not the year's first shock to the sector, and the earlier one came from an entirely different direction. While semiconductor manufacturing is concentrated in East Asia, the industry remains heavily exposed to global energy markets: around 70% of South Korea's oil imports come from the Middle East. When shipping through the Strait of Hormuz was disrupted in early March, the KOSPI fell more than 12% in a single session, its worst day on record, and lost more than 18% across two trading days, putting it on course for its steepest weekly decline since 2008.4 That episode had nothing to do with AI valuations, which is precisely the point: a sector this geographically concentrated can be repriced by events with no connection to the technology itself.

Correction or bear market?

Because semiconductor stocks are so volatile, yet increasingly widely held, the long-term direction of the market is hard to read. A bull market is conventionally defined as a rise of 20% or more from recent lows, and a bear market as a fall of 20% or more from recent highs. The sector is currently in a correction teetering on the edge of a bear market, even as the capital spending that drives chip demand continues to climb. The SOX's near-20% fall from its record puts it right at that boundary.

Strong earnings have not been enough to rescue sentiment. TSMC exceeded expectations on both profit and revenue in its second-quarter report, but paired the result with higher capital expenditure guidance than previously forecast, and its shares closed down more than 3% the following day.5 A beat that moves a share price lower is a useful signal in itself. Investors are no longer worried about whether the earnings will arrive, but about what they cost to produce. Some analysts have characterised the episode as a mid-cycle reset rather than the start of a genuine downturn, maintaining their twelve-month price targets on major chipmakers.6

Investors are no longer worried about whether the earnings will arrive, but about what they cost to produce.

What investors should watch

To understand whether the market is entering a temporary bear phase or signalling a broader downturn, investors should watch several leading indicators. Investment is the most important. Semiconductor earnings remain resilient while spending on AI and computing infrastructure is high, because that spending creates demand for chips. This is derived demand, where demand for chips depends on demand for other investment goods. On this measure the current signal is reassuring rather than ominous: the five largest hyperscalers are projected to spend between $660 billion and $690 billion on capital expenditure in 2026, close to triple the roughly $256 billion they spent in 2024.2

Manufacturing activity offers a second clue. Because semiconductors are embedded throughout industrial production, a Purchasing Managers' Index reading below 50 would suggest demand is softening beyond the AI sector. Finally, the trajectory of interest rates remains crucial. Lower borrowing costs support investment, whereas persistently high rates continue to weigh on future earnings expectations.

Whether the recent selloff marks the beginning of a prolonged downturn or merely a healthy correction will depend less on recent share prices than on the global economy. Semiconductor companies sit at the intersection of investment, technological innovation and global trade, making them one of the clearest windows into investor expectations. If AI investment remains resilient and economic growth stabilises, the recent decline may be remembered as little more than a pause in a longer bull market. If not, the sector could once again prove an early warning signal of a broader slowdown.

Footnotes

  1. CNBC, Chip stocks shed more than $1 trillion as selloff hits companies powering AI boom (opens in a new tab), 28th July 2026. 2

  2. Supply Chain Management Review, Lead time economics: What semiconductor supply chains reveal about strategic planning (opens in a new tab), 2nd July 2026. 2

  3. CNBC, AMD, Intel and Micron extend losses as chip stocks get clobbered (opens in a new tab), 27th July 2026.

  4. CNBC, South Korea stocks crashed 18% in two days. Could it happen here? (opens in a new tab), 4th March 2026.

  5. ABC News, What to know about the AI chip stock selloff (opens in a new tab), 17th July 2026.

  6. Forbes, Semiconductor Selloff Deepens As AI Spending Fears Hit Intel (opens in a new tab), 8th July 2026.