Alpha coal is priced at 6% off the benchmark price of thermal coal exports from Newcastle in Australia.

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But careful measurements over four years showed that the planet whips around Alpha Centauri B in just 3.6 days, and is estimated to have a surface temperature of about 1, 200C.

BBC: Exoplanet around Alpha Centauri is nearest-ever

Among the largest underlying components of ERX, in trading today Alpha Natural Resources Incorporated ( ANR) is up about 6.2%, and Anadarko Petroleum Corporation ( APC) is higher by about 3.4%.

FORBES: Traders Bullish on Energy ETF

Among the largest underlying components of ERX, in trading today Alpha Natural Resources Incorporated ( NYSE: ANR) is down about 3.6%, Anadarko Petroleum Corporation ( NYSE: APC) is down about 0.6%, and Apache Corporation ( NYSE: APA) is lower by about 2.1%.

FORBES: Daily Energy Bull 3x Shares Experiences Big Outflow

Among the largest underlying components of ERX, in trading today Alpha Natural Resources Inc ( NYSE: ANR) is up about 2.6%, Arch Coal, Inc. ( NYSE: ACI) is up about 2.7%, and Atwood Oceanics, Inc. ( NYSE: ATW) is higher by about 1.2%.

FORBES: ERX, ANR, ACI, ATW: ETF Outflow Alert