In the early days of the ETF industry most of the products were broad-based equity funds that offered exposure to domestic and international stock markets. But as ETFs have gained market share and become more popular with both buy-and-holders and more active traders, products have become increasingly specialized. Since the debut of the sector SPDRs in 1998, dozens of ETFs targeting various corners of U.S. and global equity markets have been introduced; recent innovations have included small cap sector ETFs, sector-specific emerging market funds. Additions to the ETF product lineup have also been increasingly granular, going beyond the nine traditional sector allocations (ten if telecom is included) to focus on sub-industries; here are multiple ETFs offering exposure to homebuilders, biotech firms, and makers of semiconductors, just to name a few. Sector ETFs can be handy for investors who believe that certain corners of the market are overvalued or undervalued relative to [...] Click here to read the original article on ETFdb.com. Related Stories: Internet ETFs Await “Cyber Monday” Results Natural Gas ETFs: Seven Ways To Play The Curious Case Of The B2B Internet HOLDRS (BHH)