Gulfport Energy Corp $8,835,957 Nephros Inc $34,757 Diamondback Energy, Inc. $14,923,048 Mammoth Energy Services, Inc. $1,237,093 Gulfport Energy Corp $8,835,957 Nephros Inc $34,757 Diamondback Energy, Inc. $14,923,048 Mammoth Energy Services, Inc. $1,237,093