ETF de crecimiento para pequeñas empresas: Un análisis histórico de la divergencia entre IJT y RZG

The performance gap between the Invesco S&P SmallCap 600 Pure Growth ETF (RZG) and the iShares S&P Small-Cap 600 Growth ETF (IJT) is a snapshot of a momentum-driven regime. But history suggests such concentrated outperformance is often fleeting and comes with heightened risk. This divergence frames a classic market cycle: a broad-based, lower-cost strategy versus a targeted, higher-fee bet on pure growth.

Structurally, the funds represent two distinct philosophies. IJT tracks the broader S&P SmallCap 600 Growth Index, offering wide exposure to the sector. RZG, by contrast, applies a stricter "pure" growth screen based on sales, earnings, and momentum, effectively filtering out companies that don't meet its aggressive criteria. This results in a stark size and cost gap. IJT commands $6.29 billion in assets with an expense ratio of 0.18%. RZG, a much smaller fund with $104.83 million in assets and a 0.35% fee, is a concentrated bet. The trade-off is clear: IJT offers diversification and lower costs, while RZG targets a subset it believes will outperform.

This setup echoes past cycles where concentrated growth strategies outperform in bull markets but falter during rotations. The recent outperformance of RZG over the last year is a familiar pattern. Yet, over a longer five-year horizon, IJT's broader approach has delivered better returns and a smaller peak-to-trough drawdown. The risk profile is also starker; RZG's max drawdown of 38.33% significantly exceeds IJT's 29.24%. This volatility is the price of the concentrated, momentum-driven strategy.

The current ETF launch frenzy, with over 1,000 new funds in 2025 and a surge in single-stock vehicles, amplifies this dynamic. It creates a market environment where niche, high-conviction strategies can gain attention and flows, much like the speculative single-stock ETFs that emerged last year. For now, RZG's momentum is intact. But the historical lens warns that such regimes are cyclical. When market sentiment shifts, the broader, lower-cost vehicle like IJT may well reassert its advantage.

What the Numbers Mean: A Historical Performance Comparison

The recent performance gap is a textbook case of momentum triumphing over stability. As of January 7, 2025, RZG's 1-year return of 12.99% nearly doubled IJT's 5.75%. This stark divergence is the hallmark of a market regime favoring pure growth, where companies with the strongest sales momentum and earnings acceleration are rewarded. It mirrors past cycles where concentrated growth strategies outperform during bull markets, capturing the leading edge of the rally. This risk differential is compounded by a key stability buffer. IJT offers a dividend yield of 0.9% compared to RZG's 0.36%. In a mean-reversion or value phase, that yield provides a tangible cushion against price declines. It represents real income that can help offset volatility, a trait often rewarded when growth momentum fades. Over the longer five-year period, IJT's broader approach has also delivered a better total return, with a $1,000 growing to $1,266 versus RZG's $1,199.

The bottom line is a trade-off that history has validated. The concentrated, higher-cost pure growth strategy can deliver explosive short-term gains when the market is in its favor. But it also carries a heavier drawdown burden and less income support. The broader, lower-cost vehicle offers a steadier path, with a yield that acts as ballast. For investors, the choice isn't just about which fund is up today, but which risk profile aligns with their view of the market's next phase.

Catalysts and Watchpoints: Navigating the Next Cycle

The current performance gap between RZG and IJT is a snapshot of a momentum regime. To test the historical analogy, investors must watch for catalysts that could validate this outperformance or trigger a rotation. The broader small-cap growth sector's health is the primary filter. As seen in the 2025 debate on large-cap concentration, a rotation away from momentum stocks could quickly pressure RZG's outperformance. The sector's recent struggles are a cautionary note; despite calls for diversification, small-caps have delivered false starts and lagged the market by about 200 basis points through November. If this broader underperformance persists, the concentrated bet in RZG will face severe headwinds.

AUM shifts are another critical watchpoint, highlighting the vulnerability of small, niche funds. RZG's $104.83 million in assets makes it highly susceptible to outflows, which could accelerate a decline in its already-concentrated portfolio. By contrast, IJT's $6.29 billion scale offers a natural stability buffer. In volatile periods, this size advantage has historically favored broader, lower-cost vehicles, as they can absorb flows more easily and maintain their strategic tilt. Any significant divergence in net flows between the two funds would be a clear signal of changing market sentiment.

Finally, monitor for changes in the competitive landscape. The underlying S&P SmallCap 600 Growth Index methodology could evolve, or new pure-growth strategies could emerge, altering the playing field. The recent launch frenzy, with over 1,000 new funds in 2025, shows how quickly niche products can gain traction. If a competing pure-growth ETF offers a similar screen with lower fees or better liquidity, it could siphon assets from RZG, challenging its premium. For now, the historical lens suggests RZG's momentum is a cyclical peak. The watchpoints above will reveal whether this regime is entering a new phase or merely a brief rally before a broader rotation.