Gulfport Energy Corp $8,505,421 Nephros Inc $34,757 Diamondback Energy, Inc. $14,820,566 Mammoth Energy Services, Inc. $1,257,541 Gulfport Energy Corp $8,505,421 Nephros Inc $34,757 Diamondback Energy, Inc. $14,820,566 Mammoth Energy Services, Inc. $1,257,541