Walmart (NYSE: WMT), the world’s largest retailer, briefly touched a $1 trillion market capitalization earlier in 2026 before slipping below that threshold to its current level above $850 billion.

Investors hoping for a swift return to the $1 trillion mark may be waiting longer than expected, as several structural and valuation concerns weigh on the stock.

Despite its global dominance in retail, Walmart remains a mature business, having posted only a 4% compound annual growth rate in revenue over the past decade.

Its most recent fiscal 2027 second quarter showed revenue growth of 5.9% year over year, which, while modestly above the long-term trend, still reflects the measured pace of a large, established enterprise.

One area of genuine excitement for Walmart bulls has been the company’s global advertising business, which surged 46% year over year during fiscal 2026, signaling strong momentum in a high-margin revenue stream.

However, that same advertising segment cooled to 38% year-over-year growth in the fiscal 2027 second quarter, raising questions about whether deceleration is becoming a persistent trend.

The core investment thesis around Walmart’s advertising arm rests on the idea that even a relatively small, high-margin business can meaningfully lift overall profit margins without needing to dominate total revenue.

If that segment continues to slow, it risks becoming too small a share of overall revenue to move the needle on margins in any significant way, undermining a key part of the bull case.

Compounding the concern is Walmart’s current valuation, which sits at a premium relative to both Amazon and Target, despite delivering revenue growth rates more comparable to the latter.

Amazon carries a price-to-earnings ratio of around 20, while Target trades at roughly 16 times earnings, making Walmart’s elevated multiple increasingly difficult to justify without a meaningful reacceleration in growth.

Until Walmart demonstrates a credible path to faster top-line expansion or a decisive margin expansion story through advertising and high-margin services, reclaiming the $1 trillion valuation threshold appears unlikely in the near term.

The combination of slowing advertising growth, a modest long-term revenue CAGR, and a stretched valuation relative to peers creates a challenging backdrop for the stock heading into the back half of fiscal 2027.