<SEC-DOCUMENT>0001103804-17-000021-index.html : 20170214
<SEC-HEADER>0001103804-17-000021.hdr.sgml : 20170214
<ACCEPTANCE-DATETIME>20170214145208
ACCESSION NUMBER:		0001103804-17-000021
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20170214
DATE AS OF CHANGE:		20170214

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PIONEER NATURAL RESOURCES CO
		CENTRAL INDEX KEY:			0001038357
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				752702753
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-51453
		FILM NUMBER:		17607425

	BUSINESS ADDRESS:	
		STREET 1:		200 WILLIAMS SQUARE WEST
		STREET 2:		5205 N OCONNOR BLVD
		CITY:			IRVING
		STATE:			TX
		ZIP:			75039
		BUSINESS PHONE:		9724449001

	MAIL ADDRESS:	
		STREET 1:		200 WILLIAMS SQUARE WEST
		STREET 2:		5205 N OCONNOR BLVD
		CITY:			IRVING
		STATE:			TX
		ZIP:			75039

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			VIKING GLOBAL INVESTORS LP
		CENTRAL INDEX KEY:			0001103804
		IRS NUMBER:				134055118
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		55 RAILROAD AVENUE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		203-863-5062

	MAIL ADDRESS:	
		STREET 1:		55 RAILROAD AVENUE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>v13ga2Pioneer.txt
<TEXT>
Document 1 - file: v13ga2Pioneer.txt

</DOCUMENT>
</SEC-DOCUMENT>