Which Growth ETF Is the Better Long-Term Buy: Vanguard's Mega Cap MGK or Invesco's Small-Cap RZG?

The Vanguard Morningstar Mega Cap Growth ETF (NYSEMKT:MGK) offers a low-cost, technology-heavy approach to the largest U.S. companies, while the Invesco S&P SmallCap 600 Revenue ETF (NYSEMKT:RZG) provides targeted exposure to small-cap growth stocks.

These two exchange-traded funds occupy different corners of the market-capitalization spectrum. The Vanguard Morningstar Mega Cap Growth ETF tracks the giants of the domestic market, focusing on firms with the highest growth potential among mega-cap stocks. Conversely, the Invesco S&P SmallCap 600 Revenue ETF looks at smaller companies within the S&P 600 that exhibit strong growth characteristics.

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.

The Vanguard fund is substantially more affordable, sporting an expense ratio of 0.05% compared to 0.35% for the Invesco fund. Over time, this 30-basis-point gap can significantly impact total returns. Both funds offer modest dividend yields below 1%.

Performance & risk comparison

What's inside

The Vanguard Morningstar Mega Cap Growth ETF provides concentrated exposure to the largest growth-oriented companies in the U.S. market. Its sector weightings are dominated by Technology at 59%, followed by Communication Services at 16% and Consumer Cyclical at 11%. Its largest positions include Nvidia (NASDAQ:NVDA) at 13.24%, Apple (NASDAQ:AAPL) at 12.14%, and Microsoft (NASDAQ:MSFT) at 7.49%. The fund holds 69 stocks in total. The fund was launched in 2007. Vanguard Morningstar Mega Cap Growth ETF has paid $0.29 per share over the trailing 12 months, which on its recent ~$90.01 share price works out to a 0.3% yield.

The Invesco S&P SmallCap 600 Revenue ETF follows a different path, focusing on a subset of the S&P SmallCap 600 Index. Its portfolio is more diversified by sector, leaning into Healthcare at 23%, Industrials at 17%, and Financial Services at 16%. The largest positions in the fund include ACM Research (NASDAQ:ACMR) at 2.33%, Dave Inc (NASDAQ:DAVE) at 2.08%, and Protagonist Therapeutics (NASDAQ:PTGX) at 1.73%. The fund holds 127 stocks in total. The fund was launched in 2006. Invesco S&P SmallCap 600 Revenue ETF has paid $0.30 per share over the trailing 12 months, which on its recent ~$70.26 share price works out to a 0.4% yield.

For more guidance on ETF investing, check out the full guide at this link.

Which looks like the better buy

The debate between megacap and small-cap investing has never been fully settled, but the past decade has delivered a decisive verdict in favor of the giants. Artificial intelligence, cloud computing, and the compounding advantages of scale have rewarded investors who stayed close to the top of the market. Companies like Nvidia, Apple, and Microsoft have grown so dominant that owning them has become less a bet on any single business and more a bet on the architecture of the modern economy itself.

Small-cap investing offers a different promise. Smaller companies have more room to grow, more sensitivity to domestic economic conditions, and historically have outperformed large caps over very long time horizons. But just not recently. RZG adds an additional quality layer by weighting its holdings by revenue rather than market cap, favoring companies with real business momentum over speculative valuations.

MGK charges significantly less than RZG and has delivered superior long-term returns, making it the stronger choice for most investors today. RZG is the more patient bet for those who believe smaller companies are overdue for their moment and want exposure grounded in actual business performance rather than market sentiment.

Sara Appino has positions in Apple and Nvidia. The Motley Fool has positions in and recommends Apple, Microsoft, and Nvidia. The Motley Fool recommends Protagonist Therapeutics. The Motley Fool has a disclosure policy.