| SC 13G | 2009-07-27 | Goodman & Company, Investment Counsel Ltd. | ARCH COAL INC | 7,367,300 | 5.1% | EDGAR |
| SC 13G/A | 2009-04-03 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 6,300,379 | 4.4% | EDGAR |
| SC 13G/A | 2009-02-17 | FMR LLC | ARCH COAL INC | 8,968,772 | 6.3% | EDGAR |
| SC 13G/A | 2009-02-17 | WELLINGTON MANAGEMENT CO LLP | ARCH COAL INC | 0 | 0.0% | EDGAR |
| SC 13G/A | 2009-02-17 | TPG-Axon Capital Management, LP | ARCH COAL INC | - | 4.2% | EDGAR |
| SC 13G/A | 2009-02-13 | Capital World Investors | ARCH COAL INC | 6,800,000 | 4.8% | EDGAR |
| SC 13G/A | 2009-02-12 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 8,056,779 | 5.6% | EDGAR |
| SC 13G/A | 2008-10-10 | FMR LLC | ARCH COAL INC | 13,131,175 | 9.1% | EDGAR |
| SC 13G/A | 2008-09-04 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 7,363,579 | 5.1% | EDGAR |
| SC 13G | 2008-07-25 | TPG-Axon Capital Management, LP | ARCH COAL INC | 1,530,400 | 5.2% | EDGAR |
| SC 13G/A | 2008-07-07 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 6,558,379 | 4.6% | EDGAR |
| SC 13G/A | 2008-04-03 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 7,373,779 | 5.1% | EDGAR |
| SC 13G/A | 2008-03-05 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 7,153,449 | 5.0% | EDGAR |
| SC 13G/A | 2008-02-14 | FMR LLC | ARCH COAL INC | 21,463,485 | 15.0% | EDGAR |
| SC 13G | 2008-02-14 | WELLINGTON MANAGEMENT CO LLP | ARCH COAL INC | 8,434,845 | 5.9% | EDGAR |
| SC 13G/A | 2008-02-13 | CAPITAL RESEARCH & MANAGEMENT CO | ARCH COAL INC | - | 0.0% | EDGAR |
| SC 13G/A | 2008-02-13 | NEUBERGER BERMAN INC | ARCH COAL INC | 253,141 | 0.2% | EDGAR |
| SC 13G/A | 2008-02-12 | CAPITAL GROUP INTERNATIONAL INC | ARCH COAL INC | 3,544,450 | 2.5% | EDGAR |
| SC 13G | 2008-02-11 | Capital World Investors | ARCH COAL INC | 7,800,000 | 5.5% | EDGAR |
| SC 13G | 2008-02-08 | PRIMECAP MANAGEMENT CO/CA/ | ARCH COAL INC | 7,157,649 | 5.0% | EDGAR |