History Says the S&P 500’s 9-Week Rally Is Rare. It May Be Even Rarer Than You Think

The stock market keeps climbing, and investors have every reason to feel optimistic. The S&P 500 closed this week with a modest 0.2% gain on Friday, enough to extend its winning streak to nine consecutive weeks. Since the market bottomed on March 30, the benchmark index has surged 19.5%, adding roughly $11 trillion in market value in just two months.

That sounds like the definition of a healthy bull market. But is it?

History suggests investors should celebrate the gains while also paying attention to what’s driving them. Because while nine-week winning streaks are rare, the makeup of today’s rally may be very different from the rallies that came before it.

Nine Weeks of Gains Is Rare, But Not Unprecedented

The current run is impressive, but it isn’t without precedent. According to historical market data, the S&P 500 has recorded 10 previous nine-week winning streaks since 1945. Longer streaks are even rarer:

At first glance, that seems encouraging. After all, if the market has done this before, perhaps investors shouldn’t read too much into it.

Granted, every rally has leaders. No bull market advances with every stock moving in lockstep. Yet today’s market structure differs dramatically from those earlier periods.

When the S&P 500 was launched, roughly 85% of the index consisted of industrial companies, with utilities accounting for 12% and railroads making up the remaining 3%. By 1963, the market remained largely centered around industrial America.

Even by 1985, when the index operated under its 400-40-40-20 structure — 400 industrials, 40 utilities, 40 financials, and 20 transportation companies — the economy was far more balanced than today’s market.

Compare that to the modern S&P 500. Technology now represents about 35% of the index. Financials account for 11%, consumer discretionary 10%, industrials 8.8%, healthcare 8.5%, and consumer staples 4.9%. Energy, utilities, materials, communications services, and real estate make up the remainder.

In other words, a handful of sectors have far more influence over the index than ever before.

This Rally Is Riding on Tech’s Shoulders

Here’s where things get worrisome. While the S&P 500 has climbed 19.5% since March 30, many sectors haven’t participated in the advance at all. Some remain below their levels from two months ago.

Instead, a small group of technology and AI-related stocks has done much of the heavy lifting.

Those are extraordinary moves in a matter of weeks.

Surprisingly, the broader economy tells a less enthusiastic story. Manufacturing activity remains uneven, consumer spending has slowed in several categories as consumer confidence has plummeted, and many economically sensitive sectors continue to lag the index.

That suggests the market’s gains are becoming increasingly concentrated in companies tied to artificial intelligence, semiconductors, memory chips, servers, and data-center infrastructure.

Key Takeaway

In short, the nine-week winning streak isn’t the red flag. The narrowness of the rally is.

Previous streaks may have been concentrated in industrial companies, but those industries reflected the dominant engine of the U.S. economy at the time. Today’s rally is being powered largely by a relatively small group of technology stocks while many other sectors struggle to keep pace.

That doesn’t mean the S&P 500 can’t continue higher. It could very well match the 10-week streak of 1963, surpass the 12-week run of 1985, or even challenge the record 13-week streak from 1957.

But investors should recognize what the numbers are saying. The “market” is reaching new highs, but much of the economy isn’t participating. When gains become dependent on fewer stocks, the market becomes more vulnerable if leadership falters.

That said, narrow rallies can last longer than skeptics expect. But it is broad participation — not a handful of AI winners — that typically makes a bull market durable. That’s the metric smart investors should be watching most closely.