The hedge fund industry is a highly secretive, mysterious one. Most funds have only the most simplistic of Web sites accessible only to their "limited partners." Mega hedge funds like SAC Capital and Perry Capital offer harsh warnings to anyone trying to view unauthorized material, or as they see it, anyone trying to get a view into their research.The Children's Investment Fund takes its security to the next level. The elusive hedge fund has no Web site. And don't let the kindly "Children's Investment Fund" name fool you; this London-based fund is known for aggressive shareholder activism. TCI, which has about $7 billion under management, was launched in January 2004 by Christopher Hohn. The value-oriented fund's name reflects the money it donates to children's charities. In 2005, via its large share of Deutsche Boerse, TCI forced the resignation of the exchange's CEO after he refused to abandon his plan to take over the London Stock Exchange. In 2006 the firm had a large position in the European Euronext exchange, but was reported to sell a large chunk of its position due to rumors that Euronext was pursuing a merger with the NYSE, as opposed to Deutsche Boerse. At Stockpickr, we track the fund's portfolio with The Children's Investment Fund. TCI's core position is CSX ( CSX), which provides railroad services in the eastern U.S. It also provides coast-to-coast intermodal transportation services linking customers to railroads, through trucks and terminals.