Ten Stocks Are Holding the S&P 500 Together While the Rest of the Market Lags Behind

TLDR:

• Only 10 stocks contributed 69% of the S&P 500’s 16% rally, leaving 490 companies largely behind.
• Microsoft, Alphabet, and Amazon pledged a combined $570B+ in AI spending, fueling the tech surge.
• The equal-weight S&P 500 gained just 7–8%, less than half the performance of the standard index.
• Goldman Sachs warned that market breadth has dropped to its narrowest level since the dot-com bubble.

The S&P 500 rally has gained nearly 16% since March 30, but market analysts are raising concerns about how few stocks are driving the move.

Just 10 companies contributed 69% of the entire index gain. The rest of the 490 companies in the index contributed only 31%.

This split between megacap performance and the broader market has drawn comparisons to conditions last seen during the dot-com bubble era.

AI Spending Surge Fuels Semiconductor Melt-Up

The rally began after reports that Iran was open to ending hostilities with the United States. Oil prices fell sharply from above $100, triggering short covering across markets. From there, strong earnings reports from major tech companies took over as the primary driver.

Several of the largest technology firms then raised their capital expenditure forecasts to historic levels. Microsoft projected AI-related spending of around $190 billion.

Alphabet guided toward $180–190 billion, while Amazon held firm at roughly $200 billion. Meta is expected to spend as much as $145 billion on AI infrastructure.

These projections pushed semiconductor stocks into a sharp upward move. Intel rose more than 240% this year. SanDisk surged over 550%. Micron doubled as AI memory demand left customers receiving only 50–67% of the chips they ordered.

As Bull Theory noted on X, “Almost every major tech company raised AI spending projections to levels never seen before,” pointing to the scale of capital flowing into AI infrastructure as the central force behind the current market move.

Narrow Breadth Raises Questions About Rally Durability

Despite the index gains, the equal-weight S&P 500 only rose around 7–8% over the same period. This version of the index removes the outsized influence of megacap stocks. That figure is less than half the performance of the market-cap-weighted index.

Fewer than half of all S&P 500 stocks are currently trading above their 50-day moving average. Goldman Sachs has warned that market breadth has fallen to one of its narrowest levels since the dot-com era. These conditions suggest the broader market is not participating evenly in the recovery.

Alphabet alone contributed 15% of the total index rally. Nvidia added another 10%. Amazon, Broadcom, Intel, Micron, Apple, AMD, and Microsoft carried the bulk of the remaining gains.

The concern among analysts is straightforward. If AI capital spending slows, if the Iran ceasefire breaks down and oil spikes again, or if earnings miss even slightly, there is limited broad market support to cushion the fall.

The rally, as it stands, rests on a narrow foundation of AI-driven stocks and one of the most aggressive corporate spending cycles in recent memory.