Like

Woody Allen

movies and

Stephen King

tomes, new

iShares

exchange-traded funds from

Barclays Global Investors

continue to roll out at a surprising pace.

On Friday, 10 more iShares funds will launch, bringing the firm's iShares fund total to 56. Since introducing iShares in May, the funds have gathered $2.6 billion in assets.

Exchange-traded funds, or ETFs, are baskets of stocks that typically replicate an index and trade as one security on a stock exchange. Many believe they pose a serious threat to traditional open-end mutual funds because they typically offer lower costs and the convenience of intraday pricing and trading. Although the value of a traditional mutual funds portfolio changes constantly throughout the day, mutual funds typically only price at the end of the trading day. (Want to know more about ETFs? Check out

Dagen McDowell's

primer,

"Everything You Want to Know About ETFs -- But Didn't Know How to Ask.")

The latest batch gives investors the opportunity to focus on different-size U.S. stocks in the growth or value style, in addition to European equities.

Small-caps are typically defined as companies with a

market capitalization below 1.5 billion.

Mid-caps usually have a market cap between $1.5 billion and $12 billion. Value stocks are typically less flashy stocks with lower

price-to-earnings, or P/E, ratios. Growth stocks are often growing at a quick pace and sport higher P/E multiples.

Below is a list of the rookies along with their tickers and expenses. Each will trade on the

American Stock Exchange.

The S&P indices focus on small- and mid-cap stocks. The Russell 3000 is a broad basket of the 3,000 largest stocks trading in the U.S. The

Russell 2000, a small-cap benchmark, is comprised of the 2,000 smallest stocks in the Russell 3000.

The S&P Europe 350 is a broad index of European securities, while the MSCI (Morgan Stanley Capital International) EMU tracks the performance of stocks in 10 European Monetary Union member countries: Germany, France, Finland, Italy, Ireland, Belgium, Austria, Portugal, Spain and Netherlands.

The average U.S. stock fund's expense ratio is 1.4%, according to

Morningstar

. The average European-focused stock fund carries a 1.74% expense ratio.