Small-cap stocks are beginning to outperform again, but ETF investors remain overwhelmingly focused on mega-cap technology and AI trades — a disconnect some strategists believe could create an opportunity in overlooked parts of the market.

The debate resurfaced after Bloomberg Intelligence analyst Eric Balchunas posted on X that small caps have effectively become "Ignored Caps," noting that small-cap ETFs once made up roughly 10% of ETF industry assets but now account for closer to 4%. At the same time, small-cap mutual funds have suffered around $25 billion in outflows even as the asset class starts regaining momentum.

Small Caps are turning into Ignored Caps.. they used to have 10% asset share in ETFs.. that's been chopped down to 4% and now they're finally outperforming and no one cares. Flows non-existent in ETFs and in MFs they've seen $25b in outflows. It's almost not fair. Good stuff… pic.twitter.com/v7mPrO7FL6

— Eric Balchunas (@EricBalchunas) May 18, 2026

The comments beneath the post reflected growing frustration that investors may be arriving late — again.

"By the time broader flows rotate back into ignored sectors, a lot of the real upside is already gone," one user wrote, highlighting a view increasingly shared across factor-investing circles.

ETF Flows Suggest Investors Still Haven't Rotated

Despite improving performance, small-cap ETF flows remain relatively subdued compared with the massive inflows still pouring into large-cap growth products tied to the AI trade.

For the past three months, funds such as iShares Russell 2000 ETF (NYSE:IWM), iShares Core S&P Small-Cap ETF (NYSE:IJR), and Vanguard Small-Cap Index Fund ETF (NYSE:VB) have lagged far behind demand for mega-cap-heavy funds like Invesco QQQ ETF (NASDAQ:QQQ) and State Street SPDR S&P 500 ETF Trust (NYSE:SPY).

Inflows for small-cap ETFs remain mixed. IJR has pulled in roughly $2.1 billion in net inflows this year, while IWM has seen around $6 billion in outflows. Elsewhere, VB has gained a mere $292 million while the Vanguard Small-Cap Growth Index Fund ETF (NYSE:VBK) shed nearly $357 million in 2026 despite 9% returns, whereas State Street SPDR Portfolio S&P 600 Small Cap ETF (NYSE:SPSM) has attracted approximately $455 million in inflows.

According to ASNM, Baron Capital Head of ETF Solutions Matt Camuso said small- and mid-cap stocks are trading at some of their most attractive valuations in decades, as soaring valuations in a handful of large S&P 500 companies have left many smaller stocks overlooked.

Why Some Investors Think This Could Be A Buying Opportunity

One of the strongest arguments emerging from the discussion is that passive investing itself may have created a valuation imbalance.

Cap-weighted ETFs automatically allocate more capital to the market's largest winners. Over the past several years, that mechanism funneled enormous amounts of money into mega-cap tech stocks, reinforcing the dominance of AI-linked names while smaller companies received comparatively little attention.

Some investors now believe the trade has become crowded.

Small caps continue trading at sizable valuation discounts relative to large-cap growth stocks, while many smaller companies could benefit disproportionately if interest rates stabilize further and economic growth broadens.

The lack of strong ETF inflows may actually strengthen the bull case.

If small caps are beginning to outperform without major retail participation, some strategists argue the rally could still be in its early stages rather than nearing exhaustion.

The Market's “Ignored Caps” May Not Stay Ignored For Long

For years, investors had little reason to look beyond mega-cap technology stocks as AI enthusiasm powered the Nasdaq and concentration inside major indexes reached record levels.

But market leadership may finally be broadening.

If flows eventually begin catching up with performance, small-cap ETFs could become one of the market's most closely watched rotation trades in the second half of 2026 — especially if investors start searching for opportunities outside the increasingly crowded AI winners.

Investors looking to build small-cap exposure can start with broad-based ETFs such as IWM, which tracks the Russell 2000 Index, or IJR, which focuses on higher-quality S&P 600 small-cap companies. Those seeking wider diversification may consider VB, while growth-focused investors can look at VBK for exposure to faster-growing small-cap names.

Analysts often recommend adding small caps gradually through dollar-cost averaging rather than making aggressive short-term bets, given the sector's historically higher volatility.

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