| Type | Filed | Filer | Subject | Shares Owned | Percent Owned | |
|---|---|---|---|---|---|---|
| SC 13G | 2015-10-07 | ADAGE CAPITAL PARTNERS GP LLC | Ocean Rig UDW Inc. | 8,507,457 | 5.3% | EDGAR |
| SC 13D | 2015-09-14 | Economou George | Ocean Rig UDW Inc. | 7,421,860 | 5.4% | EDGAR |
| SC 13G/A | 2015-08-25 | DryShips Inc. | Ocean Rig UDW Inc. | 56,079,533 | 40.4% | EDGAR |
| SC 13G/A | 2015-06-15 | DryShips Inc. | Ocean Rig UDW Inc. | 73,857,311 | 47.2% | EDGAR |
| SC 13G | 2015-02-17 | HIGHLAND CAPITAL MANAGEMENT LP | Ocean Rig UDW Inc. | 1,089,233 | 0.8% | EDGAR |
| SC 13G/A | 2015-02-09 | DryShips Inc. | Ocean Rig UDW Inc. | 78,301,755 | 59.2% | EDGAR |
| SC 13G/A | 2014-02-14 | FMR LLC | Ocean Rig UDW Inc. | 5,610,962 | 4.3% | EDGAR |
| SC 13G/A | 2014-02-06 | DryShips Inc. | Ocean Rig UDW Inc. | 78,301,755 | 59.4% | EDGAR |
| SC 13G/A | 2013-02-14 | DryShips Inc. | Ocean Rig UDW Inc. | 85,801,755 | 65.1% | EDGAR |
| SC 13G | 2013-02-14 | FMR LLC | Ocean Rig UDW Inc. | 8,310,307 | 6.3% | EDGAR |
| SC 13G | 2012-02-14 | DryShips Inc. | Ocean Rig UDW Inc. | 97,301,755 | 73.9% | EDGAR |