S&P 500 Wraps Up Best May Since 1990: 5 Top Stocks in the ETF

Wall Street recorded a historically strong May with the S&P 500 posting its best May performance since 1990, rising over 6% in the month, its biggest monthly gain since November 2023. The rally defied the traditional "Sell in May and Go Away" adage, driven by easing trade tensions, robust corporate earnings, and renewed investor optimism (read: 5 Sector ETFs That Beat the Market in May).

SPDR S&P 500 ETF Trust SPY, the proxy version of the S&P 500 Index, has gained 6.3% over the past month. While many stocks in the ETF have performed well, we have highlighted five stocks that have gained more than 25% over the past month. These include NRG Energy Inc. NRG, Seagate Technology STX, Constellation Energy Corporation CEG, Insulet Corporation PODD and Microchip Technology Inc. MCHP.

Despite growing geopolitical risks and mixed economic signals, investor sentiment remained resilient throughout May. Let’s take a closer look at the key drivers behind the market rally:

Tech Resurgence

The stock rally was brought in by the comeback in the tech stocks due to strong earnings and investor confidence in AI-driven growth.

Easing Trade Tensions

After the initial shock of the tariffs, there were signs of de-escalation. Last month, the United States temporarily slashed tariffs on Chinese goods from 145% to 30%, while China will lower its retaliatory duties on U.S. goods from 125% to 10%. The temporary reduction in rates will run for 90 days. Meanwhile, Trump also postponed the implementation of a 50% tariff increase on all EU products, from June 1 to July 9. With this, the trade negotiations between the two countries have accelerated (read: EU-US Trade Deal Hopes to Boost These ETFs). 

Additionally, the U.S. Court of International Trade (CIT) blocked much of Trump’s existing tariff policy, citing legal concerns. The ruling provided a short-lived boost to equities as the rally faded after a federal appeals court paused the CIT’s decision, prolonging uncertainty over the legal future of the administration’s “Liberation Day” tariffs.

Mixed Economic Signals

The recent economic data showed that the Federal Reserve’s preferred inflation measure cooled more than expected in April. April jobs data showed that the U.S. labor market remained resilient amid the tariff chaos. The economy added better-than-expected 177,000 jobs while the unemployment rate held steady at 4.2%, providing further assurance about the economy's health.

However, a notable slowdown in consumer spending raised concerns about the underlying strength of the economy.

Let’s take a closer look at the fundamentals of SPY and the stocks behind this rally.

SPY in Focus

SPDR S&P 500 ETF Trust holds 503 stocks in its basket, with each accounting for no more than 7% of the assets. This suggests a nice balance across each security and prevents heavy concentration. The fund is widely spread across sectors, with information technology, financials and consumer discretionary accounting for a double-digit allocation each. 

SPDR S&P 500 ETF Trust has an AUM of $603.5 billion and charges 9 bps in fees per year. It trades in an average daily volume of 68 million shares and has a Zacks ETF Rank #2 (Buy) with a Medium risk outlook (see: all the Large Cap Blend ETFs here).

Best-Performing Stocks of SPY

NRG Energy is engaged in the production, sale and delivery of energy and energy products and services to residential, industrial as well as commercial consumers in major competitive power markets in the United States. The stock saw a solid earnings estimate revision of 19 cents over the past month for this year and has an estimated growth of 10.54%. NRG Energy soared about 36% in the past month and has a Zacks Rank #3 (Hold). 

Seagate Technology is a leading provider of data storage technology and infrastructure solutions. The company’s primary product offering is hard disk drives, which are commonly referred to as disk drives, hard drives or HDDs. The stock saw a positive earnings estimate revision of 8 cents over the past month for the fiscal year (June 2025) and has an estimated growth of 516.3%. Seagate Technology jumped about 28% in a month and has a Zacks Rank #3. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

Constellation Energy provides electric power, natural gas and energy management services to 2 million customers across the continental United States. The stock gained 26.8% in a month and saw a negative earnings estimate revision of 7 cents for this year during the same time frame. Constellation Energy has an expected earnings growth rate of 9% for this year and a Zacks Rank #3. 

Insulet is a leading developer, manufacturer and marketer of the Omnipod Insulin Management System. The stock has risen 26.5% and saw a positive earnings estimate revision of 3 cents over the past month for this year, with an estimated growth rate of 33%. Insulet carries a Zacks Rank #3.

Microchip Technology develops and manufactures microcontrollers, memory and analog and interface products for embedded control systems, which are small, low-power computers designed to perform specific tasks. The stock has gained more than 25% in a month and saw a solid earnings estimate revision of 19 cents for the fiscal year (ending March 2026). Its earnings are expected to break even this fiscal year. Microchip Technology has a Zacks Rank #3. 

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This article originally published on Zacks Investment Research (zacks.com).

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