S&P 500: The Winners and Losers of June 2026
S&P 500: The Winners and Losers of June 2026
The S&P 500 pulled back slightly in June 2026, slipping roughly 1.3% to close the month at 7,499.36 after opening June at a fresh record above 7,600. The dip snapped a two-month winning streak that had lifted the index by more than 10% in April and 5% in May. It came even as market breadth quietly improved: by month’s end, a larger share of S&P 500 stocks were trading above their 50-day moving average than at the start of June. The headline decline was driven largely by weakness in a handful of mega-cap technology and AI-infrastructure names, while the broader market held up better beneath the surface.
Beneath that modest index-level pullback, individual stocks moved dramatically in both directions. In this article, we break down three of the S&P 500’s strongest performers in June and three of its weakest, and explore the company news that drove each move.
Top S&P 500 Performers in June
Among the top performers were Applied Materials ($AMAT), KLA Corporation ($KLAC), and Moderna ($MRNA). Here’s a closer look at what drove each stock’s June rally.
Applied Materials ($AMAT) +60.65%
Applied Materials, a supplier of chipmaking equipment used across the semiconductor industry, surged over 60% in June as investors piled into companies tied to AI-driven chip demand.
The rally built on a strong May earnings report, in which the company said it expected its semiconductor-equipment business to grow more than 30% in calendar 2026, citing the rapid buildout of AI computing infrastructure and its position in leading-edge logic, DRAM, and advanced packaging. That set the stage for a string of June product announcements that mapped closely onto the market’s hottest AI themes: new deposition and etching systems for advanced chip scaling on June 15, and new DRAM and advanced-packaging tools aimed at AI chips, including high-bandwidth memory applications, on June 25. Shares jumped more than 13% on June 25 alone following that announcement.
The company also announced a $500 million expansion of its Singapore manufacturing facility in early June, more than doubling its advanced cleanroom capacity to serve AI-related demand. Broader analyst enthusiasm for the semiconductor-equipment sector, including a wave of price-target increases, added further momentum to the stock.
KLA Corporation ($KLAC) +57.00%
KLA Corporation, which makes process-control and yield-management equipment for chipmakers, climbed 57% in June, riding the same AI-driven semiconductor-equipment wave that lifted Applied Materials.
Much of KLA’s fundamental strength was already visible before June began. In late April, the company reported revenue and earnings above the midpoint of its guidance and said management was “highly confident” in its calendar 2026 outlook, citing demand tied to AI infrastructure, foundry and logic manufacturing, memory, and advanced packaging. In March, KLA’s investor day added a new $7 billion share buyback authorization and a 21% dividend increase.
June’s most notable company-specific event was procedural rather than financial: KLA’s previously announced 10-for-1 stock split took effect on a split-adjusted basis on June 12, a move the company said was meant to improve accessibility and liquidity for investors. Combined with continued bullish coverage of the semiconductor-equipment sector and multiple analyst price-target increases through the month, that liquidity event helped fuel a rally that looked more like a continuation of KLA’s existing uptrend than a reaction to a single new piece of news.
Moderna ($MRNA) +48.40%
Moderna, a biotechnology company known for its mRNA-based medicines, jumped 48% in June on the back of two distinct pieces of good news.
The first came from regulators. On June 18, an FDA advisory committee voted unanimously that the benefits of Moderna’s seasonal flu vaccine for adults 50 and older outweighed its risks, a vote that followed constructive FDA staff briefing documents released two days earlier. A final approval decision is still expected by August 5, but the unanimous vote reduced a major source of uncertainty around the company’s flu-vaccine program.
The second catalyst came a week later. At its June 25 Science Day investor event, Moderna laid out plans to expand well beyond its COVID-19 vaccine roots, highlighting progress on T-cell engager therapies and introducing an early-stage “in vivo CAR-T” treatment for autoimmune disease. The company framed itself as becoming a broader, multi-modality biotechnology company, and the stock jumped sharply the next day as investors reacted to that strategic shift, with shares touching new highs on heavy trading volume.
Worst S&P 500 Performers in June
Among the worst performers were Super Micro Computer ($SMCI), Oracle ($ORCL), and Accenture ($ACN). These stocks fell sharply after company disclosures raised concerns about financing, spending, and demand.
Super Micro Computer ($SMCI) –36.36%
Super Micro Computer, a maker of servers and storage systems for AI data centers, fell over 36% in June after announcing a large capital raise to fund its AI order backlog.
On June 9, the company proposed about $7.0 billion in equity and equity-linked financing, including common stock, preferred-linked depositary shares, and an at-the-market equity program. It said the proceeds would help fund components for approximately $39 billion in AI-related orders received from more than 20 customers in recent weeks. Investors initially focused less on the size of that backlog and more on the dilution the financing would cause: shares fell nearly 8% the day the plan was announced and then dropped almost 28% the following day as the market digested the scale of the raise.
The stock partially recovered once the offering was priced on June 11 at firmer terms, but it remained under pressure for the rest of the month. Adding to the overhang, Supermicro’s own disclosures noted that the $39 billion in cited orders were not firm commitments and remained subject to cancellation or delay, which complicated the bullish backlog narrative even as new customer wins, including an AI infrastructure deal in Türkiye and a partnership tied to Nvidia’s Vera Rubin platform, continued to roll in later in the month.
Oracle ($ORCL) –35.09%
Oracle, the enterprise software and cloud-computing company, fell over 35% in June even after reporting a blowout quarter, as investors focused on the cost of funding its AI buildout.
Oracle’s June 10 fiscal fourth-quarter earnings release showed record cloud revenue, cloud infrastructure revenue up 93% year-over-year, and remaining performance obligations surging 363% to $638 billion. But the same release disclosed that free cash flow for fiscal 2026 was negative $23.7 billion and that Oracle expected to raise roughly $40 billion in additional debt and equity financing in fiscal 2027 to keep building AI data-center capacity. That financing burden overshadowed the growth numbers, and shares fell more than 8% the day after the report.
The stock kept sliding through the rest of June. A report that OpenAI, one of Oracle’s largest cloud customers, could delay its planned IPO added a fresh concern about the durability of Oracle’s AI-related demand. Late in the month, Oracle also disclosed that it had cut its workforce by about 13%, or roughly 21,000 employees, over the past fiscal year as part of a broader restructuring tied to AI-driven efficiency, which added to investor unease about the company’s cost structure even as its underlying cloud business kept growing.
Accenture ($ACN) –33.48%
Accenture, a global consulting and technology-services firm, fell over 33% in June after cutting its full-year growth guidance alongside its fiscal third-quarter results.
The company’s June 18 earnings release lowered its full-year revenue growth guidance to a range of 3% to 4% in local currency, down from a prior range of 3% to 5%, and reported new bookings of $19.3 billion, down from $19.7 billion a year earlier. Management pointed to continued softness in U.S. federal government work, along with broader caution among consulting clients, as key drags on the outlook. Shares fell about 18% on the day of the report, one of the stock’s steepest single-day declines in years.
The quarter itself was not weak across the board — Accenture posted 6% revenue growth, 9% earnings growth, and returned $3.6 billion in free cash flow to shareholders, and it simultaneously announced roughly $4.2 billion in cybersecurity acquisitions to bolster growth in that area. But investors focused on the deteriorating bookings and guidance as signs that demand for consulting services was slowing, and the stock continued to drift lower through the rest of the month rather than stabilize.
This article is for informational purposes only and is not investment advice or a solicitation to buy or sell securities. The content is based on publicly available information and reflects the author’s analysis as of the publication date, which may change without notice. All investments carry inherent risks, including the potential loss of principal, and past performance is not indicative of future results. Readers should conduct their own research or consult a financial advisor before making investment decisions.
