VTI Vs. SPY: Why Wall Street's Post-Midterm Rally Isn't as Broad as It Looks

The Democratic takeover of Congress sparked a powerful rally across Wall Street on Wednesday, lifting broad-market ETFs such as the Vanguard Total Stock Market ETF (NYSE:VTI)/a> and the State Street SPDR S&P 500 ETF Trust (NYSE:SPY)/a>. However, diverging moves among mega-cap technology stocks, semiconductor companies and AI infrastructure plays suggest the rally is not as broad-based as it appears.

VTI was up about 1.7% Wednesday. The advance came as the Dow Jones Industrial Average surged more than 3%. The S&P 500 was up 1.8%, while the Nasdaq Composite had gained about 1.8%.

The rally followed Democratic victories in both chambers of Congress, with investors betting that greater political gridlock could limit sweeping policy changes and reduce uncertainty around the economic outlook.

Mega-Cap Technology Stocks Drive the Rally

The biggest contributors to Wednesday's advance included some of Wall Street's largest technology companies, although gains were far from universal.

Apple Inc. (NASDAQ:AAPL)/a> surged approximately 6% to a record high, while Microsoft Corp. (NASDAQ:MSFT)/a> also climbed around 6%. Amazon.com Inc. (NASDAQ:AMZN)/a> advanced about 7%, providing a significant boost to large-cap equity exposure.

However, Nvidia Corp. (NASDAQ:NVDA)/a>, VTI's largest holding, fell about 1.5%. Tesla Inc. (NASDAQ:TSLA)/a>, another major holding, declined more than 2%.

The divergence matters because VTI, despite tracking nearly the entire U.S. stock market, remains heavily influenced by its largest constituents. Its top 10 holdings account for approximately 35% of the portfolio, according to Yahoo Finance data.

SPY has a similar exposure to mega-cap technology companies, as its S&P 500 benchmark is dominated by America's largest publicly traded businesses. Consequently, both ETFs are benefiting from strength in Apple, Microsoft and Amazon while facing some headwinds from weakness in semiconductor stocks.

The Catch: A Rally With Uneven Participation

The weakness in semiconductor and AI infrastructure stocks highlights the underlying tension in Wednesday's market rally.

Investors are weighing the possibility that Democratic control of Congress could bring greater scrutiny of AI development and data center construction. Democrats made significant gains in key data-center states, including Texas, raising concerns about tighter local regulations and potential delays to infrastructure projects.

Semiconductor stocks and data-center operators came under pressure even as major technology companies rallied. The Philadelphia Semiconductor Index fell more than 4% at one point, while some data-center operators suffered much steeper losses.

This creates a mixed backdrop for VTI and SPY, both of which have meaningful exposure to companies tied to the AI investment cycle.

VTI or SPY: What Should Investors Watch?

The key question is whether the post-election rally will broaden beyond mega-cap technology stocks.

If gains remain concentrated among the largest companies, SPY's exposure to the S&P 500 could remain advantageous. However, if smaller companies and other market segments begin participating more meaningfully, VTI could benefit from its broader market coverage.

For now, Wednesday's trading suggests that investors are rewarding select mega-cap technology companies while reassessing the outlook for semiconductor and AI infrastructure stocks./p> div class="bz-read-next-block" data-variant="card" data-news-mode="manual" >

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