The AI trade is moving into another big earnings test, and two semiconductor names are sitting right at the centre of it.
Nvidia and Micron are heading into earnings season with expectations already running high. But this time, the story is bigger than just two stocks.
Their results could offer investors a clearer picture of whether the massive spending on AI infrastructure is translating into real earnings growth across the broader market.
According to an analysis based on Goldman Sachs and FactSet estimates, Nvidia and Micron could account for more than one-third of the S&P 500’s earnings-per-share growth in the third quarter.
Even more striking, the two companies are expected to contribute more earnings growth than the other 490 companies in the S&P 500 combined.
That tells us something important about the market right now.
AI infrastructure is not just a technology story anymore. It is becoming a major driver of overall corporate earnings.
AI is carrying a bigger part of the earnings story
The S&P 500 is expected to post 29.5% year-over-year earnings growth for the third quarter, according to the figures cited in the source.
If that happens, it would mark the third consecutive quarter with earnings growth above 25% and the eighth consecutive quarter of double-digit earnings growth.
Wall Street is also expecting the momentum to continue.
- Q3 2026: 29.5% expected earnings growth
- Q4 2026: 27.6% expected earnings growth
- Full-year 2026: 32.4% expected earnings growth
But there is an important detail hiding behind those numbers.
AI infrastructure companies are expected to drive more than half of the S&P 500’s earnings growth for the quarter.
That makes upcoming results from semiconductor companies particularly important for investors trying to understand where the market could be headed next.
Nvidia remains the heavyweight
Nvidia is still the dominant name in the AI infrastructure trade.
The company has become one of the biggest beneficiaries of the enormous investment being made in AI computing, data centres and advanced infrastructure.
The scale of that spending is difficult to ignore.
According to the source, the five largest cloud platforms are expected to spend around $850 billion on AI infrastructure this year.
That is a staggering number.
For Nvidia, the key question is no longer simply whether AI demand exists.
The bigger question is how long this spending cycle can continue and how much of that investment will ultimately translate into sustainable revenue and earnings growth.
The source also highlights the view that the AI boom may still be relatively early in its development, despite the enormous amount of money already invested.
For investors, that creates both an opportunity and a risk.
If AI infrastructure spending continues to accelerate, Nvidia could remain a major beneficiary.
But when expectations are already extremely high, earnings and forward guidance become even more important.
Micron is becoming a bigger part of the AI story
Nvidia may get most of the attention, but Micron’s rise shows that the AI investment cycle is spreading across the semiconductor ecosystem.
Micron produces memory chips, an increasingly important component in AI infrastructure.
And its growth has been significant.
The source compares Micron’s fiscal 2025 fourth-quarter revenue of $11.3 billion with Nvidia’s fiscal 2026 second-quarter revenue of $46.7 billion.
At that point, Nvidia was generating more than four times Micron’s revenue.
Fast-forward one year and the gap had narrowed considerably.
Micron reported $54.2 billion in fiscal 2026 fourth-quarter revenue, while Nvidia reported $96.2 billion in fiscal 2027 second-quarter sales.
The difference had fallen to roughly 1.8 times.
That is a major shift.
Micron is showing just how powerful the AI infrastructure cycle can be for companies beyond the headline AI chipmaker.
Growth is where the Micron story gets interesting
Micron’s recent growth has attracted increasing attention.
The company is benefiting from strong demand for memory chips, while AI systems require significant amounts of high-performance memory.
The source points to Micron’s guidance as another reason investors are watching closely.
Micron’s guidance implies 13.4% sequential growth at the midpoint, compared with Nvidia’s midpoint implying roughly 12.2% sequential revenue growth.
Both companies have also recently exceeded their guidance.
That does not mean Micron is suddenly a larger or stronger company than Nvidia.
But it does highlight an important trend:
The AI boom is creating opportunities across different parts of the semiconductor supply chain.
Valuation changes the conversation
Growth is only one side of the investment equation.
The other is valuation.
According to the source, Micron is trading at a much lower forward P/E multiple than Nvidia.
The figures cited put Micron at around 7 times forward earnings, compared with roughly 23 times for Nvidia.
That difference is significant.
It means investors are paying a considerably higher valuation for Nvidia’s earnings than they are for Micron’s.
The market is clearly assigning a premium to Nvidia because of its dominant position in AI computing and its track record of extraordinary growth.
Micron, meanwhile, continues to carry the perception of being a more cyclical memory-chip business.
That creates an interesting debate for investors.
Does Micron’s lower valuation provide more room for upside if its AI-driven growth continues, or does the discount reflect the risks of the memory-chip cycle?
There is no simple answer.
The biggest risk for Micron: cyclicality
This is where investors need to be careful.
Memory chips have historically been a cyclical business.
When demand rises, manufacturers increase production. If supply eventually gets ahead of demand, prices can fall and inventories can build up.
That can put pressure on revenue and margins.
So while Micron’s current growth numbers are impressive, investors cannot simply assume that today’s growth rates will continue indefinitely.
The bullish argument is that AI could make this cycle different.
AI systems require significant memory capacity, and continued investment in AI infrastructure could support demand for years.
The source also points to multiyear strategic customer agreements as a factor that could potentially reduce some of the traditional cyclicality concerns.
Still, investors should keep the distinction clear:
Strong AI demand does not eliminate the cyclical nature of the memory business.
It could, however, change the scale and duration of the current demand cycle.
Why these earnings matter for the broader market
The Nvidia and Micron story matters because the semiconductor sector has become deeply connected to the broader AI investment cycle.
If these companies deliver strong results and optimistic guidance, investors could see it as confirmation that AI spending remains healthy.
That could support other technology and infrastructure stocks.
On the other hand, if results or guidance disappoint, the reaction could extend well beyond Nvidia and Micron.
Why?
Because investors are increasingly pricing AI into expectations across the market.
The higher the expectations, the more important the earnings delivery.
This is why the upcoming earnings season could provide an important reality check for the AI trade.
What investors should watch
Rather than focusing only on whether Nvidia or Micron beat earnings estimates, there are several areas worth watching.
1. Revenue growth
Are both companies still growing at the pace investors expect?
2. Forward guidance
Current earnings tell us what happened. Guidance tells us what management expects next.
3. AI infrastructure spending
Are cloud companies continuing to increase spending on AI infrastructure?
4. Memory demand
For Micron in particular, investors will be watching whether AI demand continues to support pricing and volumes.
5. Margins
Rapid revenue growth is valuable, but investors also need to see whether that growth translates into sustainable profitability.
6. Valuations
Even strong earnings do not automatically mean a stock is cheap. The market’s expectations are already high, particularly for Nvidia.
The bigger investment question
The debate around Nvidia and Micron ultimately comes down to one question:
How long can the AI investment cycle continue?
The bullish case is straightforward.
AI adoption is still expanding, cloud companies are investing heavily in infrastructure, and semiconductor demand is benefiting from that spending.
But markets rarely move on a simple growth story.
Investors also need to consider valuations, competition, capital spending, supply, demand and the possibility that expectations could eventually become too high.
For Nvidia, the challenge is maintaining exceptional growth from an already enormous revenue base.
For Micron, the opportunity could be capturing more of the AI infrastructure spending while convincing investors that this cycle can be longer and more durable than traditional memory cycles.
The bottom line
Nvidia remains the heavyweight of the AI infrastructure trade. Micron is emerging as one of the biggest beneficiaries further down the semiconductor supply chain.
Together, they could account for an unusually large share of S&P 500 earnings growth this quarter.
That makes their upcoming results worth watching even for investors who do not own either stock.
Because the real story isn’t simply Nvidia versus Micron.
It is whether the enormous investment behind AI is finally translating into earnings at a scale that can keep supporting the broader market.
And this earnings season could give investors some of the clearest evidence yet.