For most of the last three years, small-cap stocks were the market’s forgotten segment, cheap, under-owned, and consistently overshadowed by a handful of mega-cap technology names. That story has changed dramatically in 2026. The Russell 2000 (IWM) has posted its best first-half performance since 1991, climbing 22.56% and outpacing both the S&P 500’s (SPY) 10.09% gain and the Nasdaq 100’s (QQQ) 20.16% gain (Figure 1). For advisors fielding client questions about “what to do now” after years of mega-cap concentration, small caps have become one of the year’s most important conversations.

Figure 1: Source – Koyfin

What’s actually driving the rally

A 25-year valuation extreme finally closing. Heading into 2026, the iShares Russell 2000 ETF (IWM) traded at a price-to-earnings ratio of roughly 18x, versus 26x for the SPDR S&P 500 ETF (SPY). That disconnect made small caps what one portfolio manager called a “coiled spring”: once sentiment turned, there was substantial room for multiples to re-rate even without heroic earnings assumptions. Strategists describe the move as both a valuation catch-up story and a fundamental one.

The Fed’s rate-cut pivot. The Federal Reserve delivered three consecutive quarter-point cuts in late 2025, bringing the federal funds rate down to a 3.50%-3.75% range. That mattered disproportionately for small caps: nearly 40% of Russell 2000 constituents carry floating-rate debt, so lower borrowing costs flow through directly to earnings in a way they don’t for cash-rich mega-caps. Every additional 25-basis-point cut eases refinancing pressure that has weighed on smaller companies for years.

AI spending broadening beyond the mega-caps. Perhaps the most surprising driver: this is not a traditional cyclical small-cap rally led by regional banks and industrials. It has been led by semiconductor and semiconductor-equipment companies benefiting from the same AI infrastructure build-out that powered large-cap tech, just further down the supply chain. Chip-related names, like Ichor Holdings and MaxLinear, Inc, account for some of the top performing holdings of the Russell 2000 as suppliers of equipment, components, and connectivity solutions capture spillover demand from chipmakers and cloud providers ramping up AI capex.

Domestic revenue insulation. Russell 2000 companies typically generate 70-80% of revenue domestically, compared with large multinationals facing currency headwinds, tariff exposure, and China-related supply chain risk. In an environment of trade tension and a domestic manufacturing revival, reinforced by the One Big Beautiful Bill Act’s bonus depreciation and R&D expensing provisions, that domestic tilt has become a structural advantage rather than a liability.

Broadening market participation. Investors have grown increasingly wary of concentration risk in a small number of trillion-dollar companies. The rotation into small caps reflects a search for assets not already priced for perfection, and it signals, at least so far, that market leadership is broadening beyond a narrow cohort of AI winners into a wider set of sectors and balance-sheet profiles.

Where the gains have concentrated

The rally has not lifted every corner of the index equally. Semiconductor and semiconductor-equipment stocks have led by a wide margin. Industrials came in second, while health care and financials also stood out. Bank of America has noted that Russell 2000 performance has been fairly concentrated even within the rally and has favored higher-quality small-cap screens, pointing out that more than 8 in 10 companies in its preferred small-cap quality factor ETF are profitable, compared with roughly two-thirds of the broader Russell 2000.

What could derail it

The same interest-rate sensitivity that has fueled the rally is also its biggest risk. If the Fed holds rates steady longer than markets currently expect, or reverses course, the refinancing relief that has supported small-cap earnings would fade quickly, Bank of America estimates every additional 25-basis-point rate hike would reduce Russell 2000 operating earnings by roughly 2%. There’s also an earnings-delivery risk: current rally pricing assumes small-cap earnings growth accelerates meaningfully in the back half of the year, and a disappointing print could stall the valuation-normalization trade. Worth noting too: the small-cap rally has coincided with softening Main Street sentiment — the NFIB Small Business Optimism Index fell to its lowest level since October 2024 in May, a divergence between private small-business sentiment and public small-cap equity enthusiasm that’s worth watching.

The conversation for clients

For clients who spent the last few years watching a handful of mega-cap names dominate returns, 2026 has been a reminder that market leadership rotates. The small-cap story isn’t just a rebound trade, it’s supported by a genuine valuation gap, a real earnings inflection, and structural tailwinds from both monetary policy and fiscal incentives. At the same time, small caps remain a higher-volatility asset class prone to sharper drawdowns, and this year’s rally has been more concentrated in specific sectors than a simple “small caps are back” headline suggests. For portfolios that have drifted toward large-cap concentration over the past several years, 2026 offers a timely opportunity to revisit strategic allocation targets — and a reminder of why diversification across the market-cap spectrum still matters, even in a market that’s rewarded going big.

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This week on Adjusted for Risk:

Adjusted for Risk: What are the Expectations of the NextGen Advisor?

I had the pleasure of speaking with Concurrent’s Nate Lenz at the Wealth Management Edge conference.  We discussed shifts in wealth management and the rise of NextGen advisors. Additionally, we covered the aging advisor workforce amid rising demand for advice, AI as productivity and entrepreneurship enabler rather than a job threat, and the increasing importance of human relationships as some services become commoditized.

The Week Ahead

Be on the lookout for our next episode of Adjusted for Risk, where I sat down with Matt Halloran, Chief Evangelist of Zocks, to discuss the risk for advisors who do not accept AI.