Updated from 7:15 a.m. EST

Founded by Chris Hohn in 2003,

The Childrens Investment Fund

, or TCI, is a London-based hedge fund with over $15 billion in assets.

TCI, which has no Web site, has made a name as an elusive hedge fund and is known for aggressive shareholder activism. The value-oriented fund takes its name from the money it donates to children's charities.

Its top equity position is 25 million shares of

Union Pacific

(UNP) - Get Report

, which trades with a forward P/E of 9.3, PEG ratio of 0.59 and EV/EBITDA of 6.125.

TCI's second-largest position is just under 6 million shares of MasterCard

(MA) - Get Report

, an equity value of $1.1 billion. MasterCard trades with a forward P/E of 12.05, and EV/EBITDA of 7.689.

To read more,

visit Stockpickr.com

.

Stockpickr is a wholly owned subsidiary of TheStreet.com.