Navigating Market Challenges: Essential Insights for Tetra Tech Employees Amidst Tech Sector Volatility

Healthcare Provider Update: Tetra Tech's Healthcare Provider Insight Tetra Tech currently partners with various health insurance providers to deliver healthcare benefits to its employees, including prominent insurers in the marketplace. As employees prepare for upcoming benefits changes, it is critical to understand the intricacies of their coverage and options. In 2026, Tetra Tech employees are likely to experience significant increases in healthcare costs, driven by broader industry trends. With anticipated premium hikes in the Affordable Care Act (ACA) marketplace reaching over 60% in some states, many employees could see their out-of-pocket expenses soar. Factors contributing to this include the potential expiration of enhanced federal subsidies and broader medical cost inflation, which are expected to add substantial financial pressure on individuals. Consequently, Tetra Tech employees should proactively review their healthcare options and budget for potentially higher expenditures in the coming year, ensuring they are equipped to handle these economic challenges. Click here to learn more

Q1 2026 brought a striking divergence to technology markets. While the broader S&P 500 finished the quarter with a modest gain of approximately 2.4%, the technology sector experienced what analysts have dubbed the "SaaSpocalypse" - a sharp correction in business software valuations triggered by the rapid advancement of AI agents. Between January and mid-March 2026, an estimated $2 trillion in market capitalization evaporated from the software sector, with many SaaS companies seeing share prices decline 25% to 60%. Meanwhile, AI infrastructure providers and select defensive sectors surged. For employees with significant exposure to technology holdings, this divergence serves as a stark reminder that concentration in any single sector - even one that has driven market returns for years - carries meaningful risk.

What's triggering tech sector volatility? Throughout 2025, businesses across the U.S., like Tetra Tech, navigated a market environment shaped by the Federal Reserve's gradual interest rate reductions and surging AI-driven investment. But in early 2026, the rapid deployment of AI agents began disrupting traditional software business models at a pace that caught many investors off guard. Companies that had built high-growth recurring-revenue software businesses saw their valuations slashed as AI tools threatened to automate entire categories of knowledge work. At the same time, the extraordinary concentration of the S&P 500 in a handful of mega-cap technology names amplified the volatility. The Magnificent Seven - Apple, Microsoft, Nvidia, Amazon, Alphabet, Meta, and Tesla - now account for approximately 35% of the S&P 500 by market capitalization, meaning their performance has an outsized influence on index returns. When sentiment shifted in early 2026, the resulting sector rotation - out of high-growth software and into defensive names, energy, and value stocks - moved quickly.

The downside of domination
Stocks tracked by the S&P Information Technology Sector Index experienced sharp divergence in Q1 2026, with software and SaaS names hit hardest while AI infrastructure names outperformed. Plus, like many benchmark indexes, the S&P 500 is weighted by market capitalization (the value of a company's outstanding shares). This gives the largest companies, most of which are in the tech sector, an outsized role in index performance. As of May 31, the information technology sector now accounts for approximately 31% of the market cap of the S&P 500 - up significantly from years prior - compared with weightings of roughly 13% for financials and 12% for healthcare, the next-largest sectors. Nvidia, Apple, and Microsoft are among the three most-valuable companies in the index, with the full Magnificent Seven (Nvidia, Apple, Microsoft, Amazon, Alphabet, Meta, and Tesla) collectively representing approximately 35% of the entire index. ⁷

For the past several years, tech stock gains drove the market to new heights, but when their share values began to plunge, they dragged the broader stock indexes down with them. Research shows that the Magnificent Seven were responsible for approximately 42% of the S&P 500's total annual return in 2025 - a level of concentration that makes the broader index highly sensitive to shifts in sentiment toward any of these companies. ⁸

These well-known technology companies have grown into massive multinational businesses that have a major influence on everyday life. Some dominate their respective business spaces — social media, smartphones, online search and advertising, e-commerce, and cloud computing — enough to spark antitrust investigations and calls for stricter regulations in the United States and abroad. They also have plenty of cash on hand, which means they may be in better shape to withstand an economic slowdown than their smaller competitors. ⁹

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Takeaways for investors
Spreading investments among the 11 sectors of the S&P 500 is a common way to diversify stock holdings. But over time, a stock portfolio that was once diversified can become overconcentrated in a sector that has outperformed the broader market. Tech-sector stocks delivered strong total returns during 2023 through 2025, with AI-driven names generating outsized gains, so Tetra Tech employees and retirees may want to look closely at the composition of their portfolio and consider rebalancing if they find themselves overexposed to this highly volatile sector. (Rebalancing involves selling some investments in order to buy others. Keep in mind that selling investments in a taxable account could result in a tax liability.)  ¹⁰

If you feel shell-shocked after the recent market turbulence, we suggest our clients from Tetra Tech try to regain some perspective. Some market analysts view recent price declines as a painful but long overdue repricing of stocks with valuations that had grown excessive, as well as a reality check brought on by waning growth expectations. The forward price-to-earnings (P/E) ratio of companies in the S&P 500 reached approximately 22.5x heading into 2026 - approaching historical highs - before the Q1 2026 correction brought it modestly lower. ^11-12

It could be a while before investors can better assess how the economy and corporate profits will ultimately fare against AI-driven structural shifts and sector rotation pressures — and the stock market is no fan of uncertainty. Disappointing economic data and company earnings reports could continue to spark volatility in the coming months. 

It may not be easy to take troubling headlines in stride, but if you have a sufficiently diversified, all-weather investment strategy, sticking to it is often the wisest course of action. If you panic and flee the market during a downturn, you won't be in a position to benefit from upward swings on its better days. And if you continue investing regularly for a long-term goal such as retirement, a down market may be an opportunity to buy more shares at lower prices.

The return and principal value of stocks fluctuate with changes in market conditions. Shares, when sold, may be worth more or less than their original cost. Investments seeking a higher return tend to involve greater risk. Diversification is a method we suggest to our clients from Tetra Tech; it's used to help manage risk, but it's also important that Tetra Tech employees note that it doesn't guarantee a profit or protect against investment loss. The S&P 500 is an unmanaged group of securities that is considered representative of the U.S. stock market in general. The performance of an unmanaged index is not indicative of the performance of any specific investment. Individuals cannot invest directly in an index. Past performance is not a guarantee of future results. Actual results will vary. Dollar-cost averaging does not ensure a profit or prevent a loss. Such plans involve continuous investments in securities regardless of fluctuating prices. Tetra Tech employees and retirees should consider their financial ability to continue making purchases during periods of low and high price levels. However, this can be an effective way for investors to accumulate shares to help meet long-term goals.

1) SIFMA, 2022
2) Yahoo! Finance, 2022
3) The New York Times, May 31, 2022
4, 7, 10-11) S&P Dow Jones Indices, 2022
5) U.S. Bureau of Labor Statistics, 2022
6) Federal Reserve, 2022
8) The Wall Street Journal, May 19, 2022
9) The New York Times, May 20, 2022
12) FactSet, 2022