|Company||Market Cap (USD)|
|Union Pacific||$184.19 B|
|Canadian National Railway Company||$94.96 B|
|Norfolk Southern Corporation||$72.31 B|
|Canadian Pacific Railway Limited||$54.59 B|
|Beijing-Shanghai High-Speed Railway Co.,Ltd.||$36.90 B|
The market capitalization of a company, more simply referred to as "market cap", is the total market value of a publicly traded company's outstanding shares. It is often considered as a key indicator of what a company is worth.