A major structural disadvantage of ETFs is the inability to close the fund to new capital. Unlike mutual funds or SMAs, an ETF cannot stop inflows. This makes the structure inappropriate for strategies with limited capacity, such as those focused on micro-cap stocks, where large inflows would harm performance.
Contrary to intuition, even a fully systematic, rules-based investment strategy benefits from an active ETF structure. This approach avoids third-party index licensing fees and provides crucial flexibility to delay rebalancing during volatile market events, a cumbersome process for index-based funds.
The minimum seed capital for an ETF has jumped from $5M to over $25M, not due to rising operational costs, but to convey credibility. A substantial launch amount signals to the market that the fund can sustain itself for the 3-5 years necessary to build a track record and attract investors.
To compete with behemoths like Vanguard, new ETFs must focus on boutique strategies that are too complex, differentiated, or capacity-constrained for trillion-dollar managers. Competing on broad, scalable market beta is futile; the opportunity lies in specialized areas where expertise and smaller scale are advantages.
For 99% of ETFs, liquidity and bid-ask spreads are not based on the ETF's own trading activity. Instead, they reflect the cost for a market maker to buy or sell the underlying basket of securities. An ETF holding liquid stocks can trade billions with tight spreads, even if the ETF itself is rarely traded.