Gulfport Energy Corp $8,798,259 Nephros Inc $34,757 Diamondback Energy, Inc. $14,946,164 Mammoth Energy Services, Inc. $1,223,461 Gulfport Energy Corp $8,798,259 Nephros Inc $34,757 Diamondback Energy, Inc. $14,946,164 Mammoth Energy Services, Inc. $1,223,461