Claymore Securities has launched two diversified exchange-traded funds that seem almost sedate compared with its other 18 offerings.

The Claymore/Clear Mid-Cap Growth Index ETF ( MCG) and the Claymore/IndexIQ Small-Cap Value ETF ( SCV) started trading Thursday on the American Stock Exchange.

Claymore made a big splash last year when it entered the market with a series of ETFs that tracked offbeat, niche indices. Funds with names like the Yield Hog ETF ( CVY), which seeks to deliver a high income stream by investing in preferred stocks, master limited partnerships, unincorporated energy companies and closed-end funds; and the Spin-Off ETF ( CSD), which invests in recently spun-off companies, helped the company stand out in the increasingly crowded field.

So why has this market innovator suddenly gone vanilla?

In the beginning, "We didn't want to enter the ETF market issuing the 20th large-cap fund," says Christian Magoon, Claymore's senior managing director. "But after introducing these noncore funds, we received a lot of responses asking, 'Why can't you take this innovative approach and apply it to the core market?' And since the majority of people's assets are in core funds, we felt we needed to move into that area."

But even as it issues classic-style funds, Claymore still manages to tweak the model.

ETFs are basically index funds that trade continuously on a stock exchange, rather than once at the end of the trading session like mutual funds. There's currently a battle raging in the industry over the best way to create market-tracking indices.

The reigning theory says indices should be weighted by market capitalization. A company's market capitalization is determined by multiplying a stock's price by its total number of shares outstanding. The greater the market cap, the greater a company's weighting in the index. The S&P 500 and all the Russell indices are market-cap weighted.

In the other corner stands a bunch of upstarts that want indices based on fundamental metrics, such as dividends or earnings.

The debate can get quite heated, and both sides have their advantages. ETFs based on fundamental analysis include the PowerShares FTSE RAFI U.S. 1000 Portfolio ( PRF) and the Wisdom Tree family of ETFs.

While Claymore's new ETFs initially appear to be bland index funds, a closer inspection shows a lot of extra toppings filling the bowl. Claymore, seeing benefits in both theories, decided to pick and choose what it considers the best attributes and mix them together into a hybrid index.

The starting point for the Claymore/Clear Mid-Cap Growth ETF is that it screens for stocks with a market cap in the range of $2 billion to $10 billion. Then it applies fundamental metrics, such as sales, profit growth, leverage and return on equity, and valuation metrics such as price-to-earnings and price-to-earnings-to-growth.

The 50 stocks with the best ranking based on this methodology make it into the index. The fund, which has an annual expense ratio of 0.69%, is equally weighted and rebalanced on a quarterly basis.

The Claymore/IndexIQ Small-Cap Value ETF seeks to outperform the Russell 2000, the benchmark for the small-cap market. Again, the fund starts with a market-cap foundation, limiting constituents to stocks valued between $400 million and $1.5 billion.

Then it lays on a "rules-based methodology that includes composite scoring of a handful of specially targeted factors, which is scored from highest to lowest," according to the prospectus. The best 100 according to this methodology make it into the fund.

While the methodology is intriguing, the index's lack of transparency should give investors pause. Like the mid-cap fund, the small-cap fund has an expense ratio of 0.69% and is rebalanced annually.

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