October was a tough month, especially for tech and AI stocks 📉, but the S&P 500 held up relatively well.
In this recap, we look at what moved the markets, how the major indexes performed, how our portfolios compared to the market, our biggest winners and losers, and the changes we made during the month.
Dive into our full October Recap below 👇
📢 Our Best Buys for November are coming next week. Don’t miss them! 🎯
What Moved the Markets in October
October started strong, with TSMC, Nvidia and cybersecurity companies reaching new all-time highs. Apple also hit a market value of $5 trillion for the first time. But tech stocks, especially those linked to AI, came under pressure later in the month as investors questioned the huge amounts being spent on AI. The S&P 500 held up relatively well.
Earnings season brought mixed results. TSMC, ASML, SK hynix, SpaceX and Microsoft reported strong results. SK hynix also warned that memory shortages could last until 2030. Alphabet, Amazon, Intel, Adyen, Netflix and ServiceNow disappointed with parts of their results or outlooks. Adyen cut its 2026 EBITDA margin forecast to around 50% and dropped its 2028 margin target.
Cloud revenue continued to grow rapidly, with Microsoft Azure up 48%, AWS 39% and Google Cloud 103% year over year. But investors also questioned the huge costs of building AI infrastructure. Neocloud companies such as CoreWeave, Nebius, IREN and Applied Digital came under pressure over concerns about debt, financing costs and AI data center spending. Elon Musk also warned that many neocloud providers could fail or be forced to merge.
There was plenty of AI news. Microsoft unveiled its new Maia 300 AI chip, AMD introduced its Helios AI platform, and SK hynix presented MARS, a new technology for AI memory systems. Marvell sees a $400 billion TAM by 2030 and is targeting $70–90 billion in annual revenue by fiscal 2031.
Anthropic filed for an IPO under the ticker ANT, with a possible November listing at a valuation of $1.5–2 trillion. The company also made headlines as SpaceX’s largest customer, accounting for around 34.5% of its Q3 revenue.
Tesla unveiled its new flying Roadster, and there was talk about a possible Tesla–SpaceX merger, an idea supported by Elon Musk.
In Brazil, President Lula unexpectedly won the election against Flávio Bolsonaro with 51.79% of the vote. Brazilian stocks and ETFs fell hard, putting pressure on companies such as Nu Holdings and MercadoLibre.
Sea Limited also struggled as investors worried about Indonesia’s market, potentially weaker Shopee GMV, Monee’s possible IPO and its expansion into cloud services.
In the payments industry, Visa received approval to prepare for a domestic payment network in China, a potential new growth opportunity.
October also saw several big acquisitions. Schneider Electric agreed to buy PTC for $22.6 billion, DoorDash announced a $17 billion Instacart deal, Uber acquired ezCater, and Salesforce agreed to buy Braze for $5.7 billion.
Finally, Applied Materials increased its stake in BESI from 9% to around 20%, and Marvell is in talks to acquire Lumentum, which could expand its position in optical networking for AI data centers.
How did the markets react to the biggest news in October? Here’s how the three major indexes performed this month:
S&P 500: -0.9% 📉 (+10.7% YTD)
Nasdaq: -5.3% 📉 (+9.4% YTD)
Dow Jones: +1.7% 📈 (+7.7% YTD)
🔥 Upgrade Now and Save 30%!
Get full access to this Portfolio Review, our Portfolios & Transactions, our monthly Best Buys, all 15+ Deep Dives, all 95+ Stock Battles — plus 430+ premium articles to explore!
✅ Trusted by 4,800+ investors.
Portfolio Performance: How Did We Do?
How did our portfolios perform in October?
We compare our performance with the S&P 500, Nasdaq, and Dow Jones, look at our biggest winners and losers, and walk you through the portfolio changes we made during October.
Dive into the full recap below 👇
Available exclusively for our paid subscribers ✨