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.