NEW YORK ( TheStreet) -- The GlobalX Lithium ETF debuted Friday to much fanfare after a writeup in The Wall Street Journal.It's a specialized exchange traded fund, seeking to capitalize on the increase in lithium demand if electric cars proliferate and other innovations in battery technology are widely adopted. Meaningful market-share gains for electric cars will boost lithium miners and companies making lithium batteries, so the ETF allocates 50% to each category. The world's largest lithium deposits are in South America -- with the biggest in Bolivia -- although a deposit was recently discovered in Afghanistan. But the U.S. is the largest country in the fund, at 49%, followed by Chile, at 20%, and Japan, at 10%, before the allocations get much smaller. In addition to mining companies, the ETF owns companies that make the batteries. The individual holdings are concentrated -- not shocking given that this is very much a narrow slice of the equity market and the fund has only 20 holdings. Chilean materials company Quimica Y Minera ( SQM) has a 20% weight in the fund and FMC ( FMC) has 17%. Given how large these holdings are, it is important for anyone considering the lithium ETF to learn at least a little about each of those companies. Quimica Y Minera has four lines of business: fertilizer, iodine, industrial chemicals and, of course, lithium. But lithium represented only 8% of sales in the company's 2009 report. That gives the company a 31% market share, so the large weighting in the fund makes sense. Quimica Y Minera is a diversified materials company, though, not a pure play. FMC is a similar story. It has three lines of business -- industrial chemicals, agricultural products and specialty chemicals, of which lithium is a part -- but any reading I've done on the company has been in the context of discussing soda ash. The comments in FMC's 2009 report were forward-looking about the potential need for lithium and the company's recently commissioned processing plants in China and India. It seems clear that the company thinks lithium will be important for over the next 10 years, but is not significant to revenue and profits yet.