The biggest position in Pershing Square's portfolio is Canadian Pacific Railway ( CP), a $12.6 billion railroad that owns close to 15,000 miles of track that spans Canada and come of the Northeastern and Midwestern U.S. Ackman's firm owns a $1.83 billion stake in Canadian Pacific, totaling 14.2% of the firm's outstanding shares, enough to earn Ackman seats on the board this year as well as a coup in selecting the firm's CEO. Canadian Pacific earns the lion's share of its revenues by transporting commodities like coal, grain and fertilizers, no great shock given the geographic location of CP's tracks across Southern Canada. That's attractive positioning because commodities tend to be more resilient to economic headwinds than other, more cyclical freight categories like industrial goods. Canadian Pacific has tended to lag the rest of the Class I railroads in the last few years, putting up stagnant efficiency ratios while bigger railroads upped their financial performance. But with investments in fuel consumption and a push towards using longer trains, Canadian Pacific is well positioned to up its efficiency in the next few years. >>5 Volatile Stocks to Buy More Of Financially, the firm has felt some ill effects from having to maintain those thousands of miles of track: the firm has a lot more debt than its peers do. But that comparison is exacerbated by the fact that its peers have trimmed their own debt loads of late. Despite the bigger debt load, CP should have no trouble covering its obligations with the amount of cash it generates.