Apple vs Alphabet: Who ends October as the second-largest company?

Apple's stock price is up more than 23% this year, while Alphabet’s is up just under 8%. As of this writing, Apple boasts a market cap of $4.87 trillion versus Alphabet’s $4.18 trillion. That’s about $680 billion in favor of Apple as the battle for the second-largest company by the end of October heats up on Polymarket.

Traders are overwhelmingly in favor of Apple retaining its current position behind Nvidia (which is strongly favored to end the month as the biggest company in the world by market capitalization, with a 96% chance.

The AI data center giant is also a strong favorite to end the year as the world's largest company by market cap, with an 85% chance on Polymarket, versus Apple’s 10%. Last week, when we covered this market, Apple had a 16% chance versus Nvidia’s 76%. With the figures changing, Apple seems to be clearly battling for second.

The iPhone maker is leading the race to be the second-largest company in October. Polymarket traders are giving Apple a 93% chance versus Alphabet’s 4%. Interestingly, Nvidia ranks third in this market, with a 3% chance. 

Volume data also suggests traders see Apple as the second-largest company by market cap at the end of October, with nearly $11k locked versus just $587 on Alphabet.

Are Polymarket traders overpricing Apple’s chances of being second?

The $680 billion difference in valuation between Apple and Alphabet means that there is just a 16% difference, and this can be wiped out with a single-digit move up from Alphabet and a similar move in the opposite direction for Apple.

So what are the chances of getting these two opposing moves before the end of the month? Let’s look at potential valuation catalysts for both companies.

Apple recently released its latest version of the iPhone, the iPhone 18 Pro line-up, whose sales, alongside the iPhone 17 sell-throughs, will be the primary value catalysts between now and the end of the year.

The company has already demonstrated a strong performance according to first-week numbers from China, with 15% more sales than last year’s iPhone 17 Pro line-up. In India, first-day sales data were also reportedly 20%-30% higher than the iPhone 17s.

As more numbers continue to come out during October and confirm a potential outperformance of last year’s numbers, Apple could be poised to retain its position as the second-largest company by the end of October.

The few betting on Alphabet, on the other hand, will be keeping an eye on Gemini adoption and Google Cloud growth and margins. The company is expected to report its Q3 earnings on October 28, with three days of trading left for a potential post-earnings price action.

Investors will also be looking at the AI capex ROI after spending more than $44 billion in Q2, driven by AI. The company now expects to spend between $195 billion and $205 billion in 2026. AI investments helped Alphabet’s profits grow fourfold in the previous quarter.