May 18, 2026 – AI, semiconductor, and space stocks led Wall Street last week. Strong earnings and analyst upgrades fueled the surge across nine large-cap names.
In Summary
Tower Semiconductor (TSEM) led all gainers, jumping 28.5% after securing a $1.3 billion silicon photonics contract and guiding record Q2 revenue of $455 million.
Cisco Systems (CSCO) surged 22.4% on a strong Q3 earnings beat, while Venture Global (VG) rose 23.0% on better-than-expected Q1 results.
Rocket Lab (RKLB) climbed 18.1% following record Q1 revenue of $200.3 million, up 63.5% year over year, and a $2.2 billion order backlog.
Palo Alto Networks (PANW) added 16.8% as multiple Wall Street analysts raised their price targets on the cybersecurity giant.
All nine gainers were driven by company-specific catalysts, not broad market tailwinds. Macro conditions remained largely neutral last week.
Large-cap technology and AI-linked stocks dominated Wall Street’s list of top gainers last week. Investors rotated into names tied to semiconductor demand, cybersecurity, and space infrastructure. Furthermore, strong earnings and upbeat guidance drove momentum across multiple sectors.
Nine stocks posted double-digit gains between May 11 and May 15, 2026. Each move was triggered by company-specific news, not a broad market rally. However, the common thread was clear: AI spending continues to reshape capital allocation on Wall Street.
Tower Semiconductor Leads the Pack
Tower Semiconductor TSEM was the week’s biggest winner. Shares jumped +28.48% following a double catalyst. First, the company reported strong Q1 2026 results. Second, it announced a landmark silicon photonics deal.
Revenue for Q1 2026 reached $414 million. That represents 15% year-over-year growth, according to Tower’s official earnings release. Furthermore, net profit surged 62% to $65 million. Operating profit nearly doubled, rising to $65 million from $33 million in Q1 2025.
The standout news was the silicon photonics contract. Tower secured $1.3 billion in contracted silicon photonics revenue for 2027. Additionally, customers paid $290 million in prepayments to reserve capacity. CEO Russell Ellwanger described the $1.3 billion as a contractual floor, not a ceiling.
Moreover, Tower guided record Q2 2026 revenue of $455 million. That implies 22% year-over-year growth and 10% sequential growth. The company also reiterated long-term targets of $2.8 billion in annual revenue and $750 million in net profit by 2028. Therefore, investor enthusiasm was well-founded in verifiable financial data.
Rocket Lab Hits Record Revenue
Rocket Lab (RKLB) shares rose +18.08% last week. Investors continued to respond to a blockbuster first-quarter earnings report published on May 7, 2026. Therefore, the stock gained on continued post-earnings momentum.
Q1 2026 revenue hit $200.3 million. That is a 63.5% year-over-year increase and a new company record, according to Rocket Lab’s official earnings statement. Moreover, the company’s backlog reached $2.2 billion, surpassing Wall Street’s $2 billion estimate.
Several major defence contracts underpin that backlog. The U.S. Department of Defence placed a $190 million order for 20 hypersonic test flights using Rocket Lab’s HASTE vehicle. Additionally, Anduril signed a $30 million deal for three HASTE launches. Consequently, Rocket Lab is evolving from a launch company into a space infrastructure provider.
“Rocket Lab posted Q1 revenue of $200.3M, up 63.5% year over year, setting a new company record.”
Source: Rocket Lab Q1 2026 Earnings Statement
For Q2 2026, management guided revenue between $225 million and $240 million. Non-GAAP gross margins are expected to be at 38% to 40%. Multiple analysts responded with price target hikes. TD Cowen raised its target to $120. Needham set a $120 target, implying further upside from current levels. However, Goldman Sachs maintained a Hold rating, signalling some caution at current valuations.
Palo Alto Networks Climbs on Analyst Confidence
Palo Alto Networks (PANW) gained +16.76% last week. Multiple Wall Street firms raised their price targets in the five-day window. Moreover, channel checks showed positive demand signals across Palo Alto’s product lineup.
BTIG raised its price target to $216 from $200 on May 6, 2026. The firm cited partner checks representing $1.6 billion in annual Palo Alto sales. Prisma SASE emerged as the standout product, noted by all seven product-level contacts surveyed, according to Investing.com. Additionally, CEO Nikesh Arora purchased 68,085 shares in late March, signalling strong insider conviction.
The broader cybersecurity theme also helped. Fortinet’s strong results calmed fears about AI disruption in the sector. Therefore, Palo Alto benefited from a sector-level shift in sentiment as well as its own company-specific catalysts. Its full-year revenue guidance is $11.28-$11.31 billion, representing 22–23% growth.
Other Notable Gainers This Week
Venture Global (VG): +22.99%
Venture Global led the LNG-linked stocks higher last week. Shares rose after the company reported better-than-expected first-quarter financial results. However, the company provided limited additional forward guidance.
Cisco Systems (CSCO): +22.40%
Cisco surged after reporting upbeat third-quarter results. The networking giant continues to benefit from enterprise AI infrastructure upgrades. Consequently, investor enthusiasm extended beyond the immediate earnings release.
Nebius Group (NBIS): +21.25%
Nebius climbed over 21% on a strong Q1 report. The company also raised its contracted power guidance, signalling confidence in AI data centre demand. Furthermore, the stock continues to attract attention as a European AI infrastructure play.
The Bigger Picture
Last week’s gainers share a common narrative: AI infrastructure spending is real and accelerating. Tower Semiconductor’s silicon photonics contracts reflect growth in AI data centres. Rocket Lab’s defence wins reflect geopolitical investments in space capabilities. Palo Alto’s analyst upgrades reflect the growing enterprise security budget.
Notably, all nine stocks moved on company-specific catalysts. The S&P 500 was essentially flat during the same period. Therefore, stock pickers who held these names were rewarded by fundamentals, not by macro luck. However, elevated valuations remain a risk. Several of these names now trade at significant premiums to sector peers.
Looking ahead, Tower Semiconductor’s Q2 guidance and Palo Alto’s fiscal Q3 results due June 2 will be the next key data points. Additionally, progress on Rocket Lab’s Neutron rocket in late 2026 could reshape the stock’s trajectory. Investors should monitor earnings delivery versus these elevated expectations.
