The iShares Russell 2000 Growth ETF (IWO +0.31%) targets small-cap companies while the Vanguard Morningstar Mega Cap Growth ETF (MGK -0.69%) focuses on the largest U.S. growers, presenting a choice between niche agility and blue-chip stability.

Investors seeking growth often grapple with the trade-off between the stability of market titans and the explosive potential of smaller firms. While the Vanguard fund provides concentrated exposure to the tech giants driving modern markets, the iShares fund offers a broader, healthcare-heavy basket of smaller innovators. This analysis compares their costs, risk profiles, and unique portfolio structures.

Snapshot (cost & size)

Beta measures price volatility relative to the S&P 500; beta is calculated from monthly returns over the available fund history (up to five years). The 1-yr return represents total return over the trailing 12 months. Dividend yield is the trailing-12-month distribution yield.

Cost is a primary differentiator here, as the Vanguard Morningstar Mega Cap Growth ETF maintains a minimal 0.05% expense ratio, making it much more affordable than the 0.24% charged by the iShares Russell 2000 Growth ETF. While the iShares fund offers a slightly higher 0.4% yield compared to the Vanguard fund's 0.3%, both payouts remain secondary to price appreciation for these growth-focused strategies.

Performance & risk comparison

What's inside

The iShares Russell 2000 Growth ETF targets smaller, high-growth companies, with its largest sector allocations in healthcare at 29%, technology at 21%, and industrials at 15%. Its portfolio is broadly diversified among 1,106 positions; its largest positions include Moog (MOGA +1.76%) at 0.70%, Glaukos (GKOS +0.32%) at 0.63%, and Brightspring Health Services (BTSG -5.79%) at 0.62%. It was launched in 2000. The iShares Russell 2000 Growth ETF has paid $1.64 per share over the trailing 12 months, which on its recent ~$388.02 share price works out to a 0.4% yield.

By contrast, the Vanguard Morningstar Mega Cap Growth ETF focuses on the absolute largest growers, concentrating 59% of assets in technology, 16% in communication services, and 11% in consumer cyclical sectors. It is much more top-heavy with only 69 holdings; its largest positions include NVIDIA (NVDA -0.02%) at 13.24%, Apple (AAPL -1.09%) at 12.14%, and Microsoft (MSFT -0.45%) at 7.49%. It was launched in 2007. The Vanguard Morningstar Mega Cap Growth ETF has paid $0.29 per share over the trailing 12 months, which on its recent ~$90.63 share price works out to a 0.3% yield.

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Which looks like the better buy?

You really can’t find two more different ETFs than these. They probably both belong in your portfolio, since they cover the gamut of U.S. stocks between the two of them.

The Vanguard ETF invests in the largest end of the spectrum, the megacap monsters that have dominated the markets for the past 10 years or more. The long-term returns for this ETF dwarf the returns of the iShares ETF, with an average annualized return of nearly 19% over the past 10 years compared to 11% for the small-cap fund.

But year-to-date, and over the past year, small-caps have dominated. The iShares ETF is up 19% YTD and 33% over the past 12 months. In contrast, MGK is up 9% YTD and 17% over the past year. This outperformance occurs as investors rotate out of overvalued large-cap stocks into less expensive smaller caps. But also, AI innovations are starting to expand beyond tech and large-caps, benefitting smaller companies.

If I had only to invest in one, I might invest in IWO because historically, small-caps have led the way following a sustained large-cap driven bull market. Plus, you will get access to these megacap stocks in an S&P 500 ETF, which many investors already own.