Chip stocks lose a key support as the SOX slips below its 200-day average

The semiconductor trade that powered the AI boom just lost one of its most watched safety nets.

The PHLX Semiconductor Index, better known as the SOX, closed below its 200-day moving average on Friday. It is the first time that has happened since May 2025.

What broke, and by how much

The SOX tracks a basket of major chip designers, manufacturers and equipment makers. It has become shorthand for the AI hardware trade, since those are the companies supplying the processors and gear that fill data centers.

The index now sits roughly 40% below its June 22 high, according to BTIG. That peak came in at 14,634.

The move below the 200-day line came after a wave of broad selling. Semiconductor and AI names were hit especially hard as investors unwound positions that had been crowded for a long time.

Why the 200-day line gets so much attention

Think of the 200-day moving average as a stock’s long-term mood ring. It averages the closing prices over the last 200 trading sessions, which smooths out daily noise.

When an asset trades above that line, traders generally read the long-term trend as healthy. When it closes below, many read it as a sign the trend may be turning.

Its power comes partly from how many people watch it. Funds and traders who use trend-following rules often adjust exposure when a major index crosses the line, which can add fuel to a move already underway.

The SOX had stayed above this level since May 2025. That makes Friday’s close less like a stumble and more like the end of a long winning streak.

The question hanging over AI spending

The technical break did not happen in a vacuum. It arrives as investors push harder on a basic question: will the enormous sums being poured into data centers ever earn enough to justify the cost?

Large tech companies have been spending heavily on AI infrastructure, and chipmakers have been among the most direct beneficiaries. The worry is that if the businesses buying all that hardware cannot show strong returns, they may eventually slow their spending.

What this means for investors

The 40% drawdown from the June 22 peak shows how concentrated bets can unwind quickly. When a trade becomes a consensus favorite, the exit can get crowded fast once sentiment turns.

There is also a broader market dimension. The SOX has been one of the market’s key AI trades, so weakness here can ripple into wider indexes where chip and AI stocks carry heavy weight.

For traders, the 200-day line itself now becomes a reference point. A recovery back above it would suggest the break was a false alarm, while repeated failures to reclaim it would reinforce the idea that the trend has changed.