The ETF industry has engaged in an internecine price-war that has pushed expense ratios closer and closer to zero, ultimately benefiting the end investor.

There are now U.S.-listed 1,978 exchange traded products, which include both ETFs and exchange traded notes, with $2.6 trillion in assets under management and an average expense ratio of 0.57%, according to XTF data. The cheapest ETF options include broad U.S. stock strategies with a dirt cheap 0.03% expense ratio, including the iShares Core S&P Total US Stock Market ETF (NYSEArca: ITOT), Schwab U.S. Large-Cap ETF (NYSEArca: SCHX) and Schwab U.S. Broad Market ETF (NYSEArca: SCHB).

Moreover, some providers, like Charles Schwab and Fidelity Investments, are offering their ETFs with commission-free trades on their respective brokerage platforms.

As the ETF industry continues to grow, we will likely witness the continued fall in traditional actively managed open-end mutual funds, especially those that have consistently underperformed and charged high fees – the S&P has found that about 80% of active managers have failed to outperform for years.

Among the hot new areas in ETFs, smart beta or alternative factor-based index ETFs are all the rage. These smart beta themes combine actively managed styles in a passive rules-based index structure to help investors potentially enhance returns and diminish risks.

With the continued growth in the ETF space, more money managers and even mutual fund firms are crafting ETFs. As many plain vanilla index-based themes are already well populated, ETF sponsors have increasingly turned to niche or focused strategies to slice the markets into smaller segments.