The curtain is about to drop on 2011, a year that will go down as a record-breaking period for the rapidly-expanding ETF industry. More than 300 exchange-traded products began trading this year, with dozens of issuers rolling out new products. While some of the new additions bear a striking resemblance to more established products on the market, the recent growth has been market by innovation that has made new asset classes and strategies available through the exchange-traded wrapper. In a year full of ETF firsts, a few developments are particularly noteworthy; below, we highlight some of the events of the past year in the ETF world that have had the biggest impact on the way financial advisors and investors manage their portfolios [for more ETF insights, sign up for the free ETFdb newsletter]: 1. Investment Discipline / Factor ETFs One of the more exciting developments over the last year has [...] Click here to read the original article on ETFdb.com. Related Posts: 2011: A Year Of ETF Firsts Six Noteworthy ETF Innovations June ETF Roundup: Launches, Filings, and Closures PowerShares Rolls Out Inverse, Leveraged Japanese Bond ETNs ETF Sector Rotation Strategies: Beyond The SPDRs