The Rally Is Real. The Question Is How Many Stocks Are Actually In It.

The S&P 500 just hit fresh all-time highs. The semiconductor index went 22 for 23 sessions. AI-driven earnings growth is real and accelerating. And yet Goldman Sachs flagged this week that market breadth has dropped to its narrowest level since the dotcom era. Goldman's preferred measure tracks the gap between the index's distance from its 52-week high and the median stock's distance from its own, and that gap has not been this wide since 2000. Separately, only about 55 to 60% of S&P 500 stocks are currently trading above their 200-day moving average, a level that typically signals weak participation even when the index itself is making new highs.. The top ten companies in the index now represent roughly 40%  of total market cap, well above the 27% concentration seen at the peak of the dot-com bubble. The index looks great. The market underneath it is a different story.

The key observation is that the S&P 500 and the average stock in it are describing two different environments right now, and experienced investors have historically known to look at both.

The driver is no mystery. Since the Iran War began late February, the iShares Semiconductor ETF has jumped 30%. AI infrastructure is the rally. Goldman estimates that AI-related investment will drive roughly 40% of S&P 500 earnings growth this year, concentrated in roughly a dozen names. Meanwhile most of the other 488 companies in the index have tread water or worse. The Russell 2000, the small-cap index that historically signals broad economic participation, is lagging meaningfully. Schwab clients, tracked by the firm's STAX index, made a notable rotation deepened in April out of higher-beta individual holdings and into broad-based lower-beta ETFs, the second consecutive monthly decline in risk appetite. The headline says bull market. The internals say something more selective.

On Sunday evening, August 15, 1971, Richard Nixon interrupted regular television programming.

He spoke for 15 minutes.

By the time he finished, the gold standard was over. The dollar was no longer backed by anything except the government's word. And every dollar in every American's savings account had quietly changed — not in number, but in what it actually meant.

Nixon didn't ask Congress. He didn't hold a debate. He used a single executive authority and by Monday morning the monetary world had shifted.

The people who saw it coming had already moved. Gold tripled in three years. Over the next decade it went up twenty times.

The people who didn't understand what was happening watched their savings quietly lose value for a decade. They never recovered it.

Here's what the financial press isn't saying clearly:

Trump has that same executive authority today. And his own advisors are now openly saying the reversal of what Nixon did is on the table.

If he acts, it moves fast. There are two ways this plays out. Both of them move gold in the same direction.

We put together a free briefing on exactly what Nixon did, why Trump is the first president positioned to reverse it, and the one move Americans can make right now to be on the right side of what comes next.

Free. 30 seconds to request.

Nixon didn't warn anyone before that Sunday night broadcast.

Trump's advisors are warning you right now.

GET THE FREE GUIDE

This is typically classified as a narrow leadership environment. A small group of stocks is doing the work for the whole index, while the majority of names lag or go sideways. These environments are not inherently bearish. Narrow markets can persist for extended periods, particularly when the leading names have genuine structural earnings tailwinds, which the AI cohort clearly does. Goldman's own view remains constructive, targeting 7,600 on the S&P 500 by year-end. But as Goldman's strategists put it directly: narrow breadth is not a sell signal. It is a fragility signal.

Experienced investors focus on whether leadership is broadening or further narrowing, not just where the index is trading. One key signal is small and mid-cap performance relative to large caps. A sustained period of Russell 2000 outperformance would suggest the rally is finding legs beyond the AI megacap cohort, which historically makes it more durable. Another signal is earnings breadth, specifically whether the 84% beat rate of this earnings season is producing positive stock reactions across sectors or just in tech and AI-adjacent names. Investors also watch the advance-decline line, which measures how many stocks are rising versus falling on any given day, as a real-time read on whether participation is improving or deteriorating beneath the surface.

A common misread is treating a record index level as evidence of broad market health. The top ten companies now account for 40% of the S&P 500's market cap, well above dot-com era peaks. Index strength and broad market strength are not the same thing at this concentration level. Another misread is assuming narrow breadth predicts an imminent correction. Goldman's data shows narrow breadth historically indicates fragility and drawdown risk, not a specific timing for when that risk materializes. There is also a tendency to confuse the performance of mega-cap stocks with the performance of the average investor's portfolio, which often has very different exposure than the index suggests.

Focus on participation, not just performance.

The distinction between an index level and market breadth is one of the most practically useful frames in investing. The mental model here is width versus height. The market can climb to new heights on a narrow base for longer than most people expect. What history consistently shows is that when that narrow base eventually shifts, the move tends to be fast and the concentration that powered the rally becomes the mechanism that amplifies the unwind.

Narrow leadership environments resolve when either participation broadens, pulling the rest of the market up to meet the leaders, or when the leaders falter and the narrow base is exposed. The AI earnings story has genuine fundamental support, which is what separates the current setup from the most extreme historical analogues. Whether that support is strong enough to either broaden participation or sustain the index on its own is the question the next several months of earnings and economic data will answer.

Talk soon,
The Playbook Daily