ࡱ> NO l \pThe Free Software Foundation B=PF0*8X@"1 Helvetica1Courier1 Courier New1 Courier New1 Helvetica$#,##0_);($#,##0)$#,##0_);[Red]($#,##0)$#,##0.00_);($#,##0.00)$#,##0.00_);[Red]($#,##0.00)-**_($* #,##0_);_($* (#,##0);_($* "-"_);_(@_)*)'_(* #,##0_);_(* (#,##0);_(* "-"_);_(@_)5,2_($* #,##0.00_);_($* (#,##0.00);_($* "-"??_);_(@_)2+/_(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(@_)2$#,##0.00;[Red]$#,##0.003$#,##0.00;[Red]($#,##0.00)4$#,##0;[Red]($#,##00)50.00%;[Red](0.00%)6 0%;[Red](0%)7#,##0.00;[Red](#,##0.00)8#,##0;[Red](#,##0)                + ) , *   Ј ~~ ؈ ~~#؈ ~~ ؈ ~~8#܈ ~~9#܈ ~~83ffff̙̙3f3fff3f3f33333f33&With Report of Independent Regi&With Report of Independent (1)&fWith Report of Independent (2)$+Pioneer Stock Investment Fund$3Pioneer Stock Investment (1)$R;Pioneer Stock Investment (2)$KDPioneer Stock Investment (3)&iLSchedule H Line 4i ndash Schedu&slSchedule H Line 4i ndash Sc (1)&%tSchedule H Line 4i ndash Sc (2)&{Schedule H Line 4i ndash Sc (3)&Schedule H Line 4i ndash Sc (4)&1Schedule H Line 4i ndash Sc (5)&Schedule H Line 4i ndash Sc (6) l  !2 dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } 6} $ }  !    $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008D<With Report of Independent Registered Public Accounting Firm Page   / 'Report of Independent Registered Public ~  Accounting Firm   .&Statements of Net Assets Available for~ 1)Benefits as of December 31, 2021 and 20064,Statement of Changes in Net Assets Available~ 'for Benefits for the Year EndedDecember 31, 2007%Notes to Financial Statements~ 0(Schedule H; Line 4i - Schedule of Assets~ :5-(Held At End of Year) as of December 31, 2007 Signatures~ >Index to Exhibits~ B$____________________________1)Created by Morningstar Document Research.Dl^RF:bk@#JbVJ 0 (http://documentresearch.morningstar.com/H=PF0*8X> @  l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } :} m     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008D<With Report of Independent Registered Public Accounting Firm December 31, ~ ^~ Z ! Investments at fair value $ 192,958,904 $ 168,242,423$ Participant loans receivable~ ZD~ C~ :.~ (3+Unallocated accrued administrative expenses -~ j2*Net assets available for benefits, at fair~ :.~  (value.&Adjustment from fair value to contract~ .~ :*"value for fully benefit-responsive80investment contracts held by a common/collectivetrust)!Net assets available for benefits$ 196,858,969$ 171,594,256$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/@+D^RF:G#3"jY5=PF0*8X> @" l  ")* dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } 8} m "    $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008D<With Report of Independent Registered Public Accounting Firm7/Additions to net assets available for benefits:$ Interest and dividend income  $ 10,911,543 Employer contributions~ ,# Participants' contributions~ B5 -Net appreciation in fair value of investments~  Rollovers~ [: Other income~ ~yTotal additions~ ~0(Deductions from net assets available for benefits:%Distributions to participants~ VAdministrative expenses~ kTotal deductions~ Z0(Net increase in net assets available for~ & benefits4,Net assets available for benefits, beginning~ BH(of year.&Net assets available for benefits, end$ 196,858,969of year$____________________________D[l^RF:N}=(~<(lY !1 )Created by Morningstar Document Research.0!(http://documentresearch.morningstar.com/=PF0*8X> @!!  l  h3 dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } m)} <     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008%Pioneer Stock Investment Fund December 31, ~ ^~ Z  Vanguard PRIMECAP Fund  $ 40,148,842  $ 37,308,588 Vanguard Windsor II Fund  $ 26,996,659  $ 26,183,514Vanguard 500 Index Fund $ 25,323,499 $ 22,652,092( Vanguard Prime Money Market Fund $ 18,006,113 $ 14,412,010*"Vanguard International Growth Fund $ 14,380,956 $ 9,889,272Sarofim Equity Fund $ 13,867,619 $ 12,722,017$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/0a}qeY5[O=PF0*8X> @" l  : dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } 6}       $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008%Pioneer Stock Investment Fund+#Registered investment company funds $ 252,836 Common/collective trusts~ .C% Pioneer Stock Investment Fund~ F:v  5 -Net appreciation in fair value of investments  $ 3,289,024$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(T}qeYD8,=PF0*8X> @ l  C dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } 2} m     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008%Pioneer Stock Investment Fund December 31, ~ ^~ Z 1 )Net assets available for benefits per the $ 196,858,969 $ 171,594,256 accompanying financial statements.&Adjustment from fair value to contract~ 9 -2*value for certain fully benefit-responsiveinvestment contracts2*Net assets available for benefits per Form$ 196,911,822$ 171,594,256~ U$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/4]}qeY5x]. =PF0*8X> @" l  K dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } U5} <     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008%Pioneer Stock Investment Fund0(Net increase in net assets available for $ 25,264,713/ 'benefits per the accompanying financial  statements4 ,Plus: Adjustment from fair value to contract~ 92 *value for certain fully benefit-responsive1)investment contracts at December 31, 2007"Net increase per Form 5500 $ 25,317,566$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/.}qeY~H}=PF0*8X> @ l  M'[kgk dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } } <(} 1} m M    $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year) (c)  (b)+ #Description of investment including (e) % Identity of issuer, borrower,(  maturity date, rate of interest, Current (a) lessor, or similar party) !collateral, par or maturity value Value     *( Vanguard Fiduciary Trust Company/'Vanguard PRIMECAP Fund - 557,236 shares $ 40,148,842 *( Vanguard Fiduciary Trust Company1)Vanguard Windsor II Fund - 863,617 shares~ ξo *( Vanguard Fiduciary Trust Company0(Vanguard 500 Index Fund - 187,373 shares~   *( Vanguard Fiduciary Trust Company*"Vanguard Prime Money Market Fund -18,006,113 shares~ K *( Vanguard Fiduciary Trust Company,$Vanguard International Growth Fund -~ rm579,410 shares *( Vanguard Fiduciary Trust Company/'Vanguard Explorer Fund - 118,596 shares~ O *( Vanguard Fiduciary Trust Company+#Vanguard Retirement Savings Trust -~ Z6,932,492 shares *( Vanguard Fiduciary Trust Company,$Vanguard Short-Term Investment-Grade~ !Fund - 612,489 shares *( Vanguard Fiduciary Trust Company( Vanguard Asset Allocation Fund -217,164 shares~  *( Vanguard Fiduciary Trust Company( Vanguard Total Bond Market IndexFund - 635,294 shares~ D lWK?33ah4T !"#$%&'()*+,-./0123456789:;<=>? *(  Vanguard Fiduciary Trust Company/ 'Vanguard Inflation-Protected Securities !!!~ !i"""Fund - 315,060 shares #*(# Vanguard Fiduciary Trust Company.#&Vanguard Target Retirement 2010 fund -#$$$~ $6g%%%73,745 shares &*(& Vanguard Fiduciary Trust Company.&&Vanguard Target Retirement 2015 fund -&'''~ 'ʀ@(((80,920 shares )*() Vanguard Fiduciary Trust Company.)&Vanguard Target Retirement 2020 fund -)***~ *5+++37,633 shares ,*(, Vanguard Fiduciary Trust Company.,&Vanguard Target Retirement 2035 Fund -,---~ -Ƌ+...48,800 shares /*(/ Vanguard Fiduciary Trust Company./&Vanguard Target Retirement 2025 Fund -/000~ 02&(11147,945 shares 2*(2 Vanguard Fiduciary Trust Company-2%Vanguard Extended Market Index Fund -2333~ 3!44413,762 shares 5*(5 Vanguard Fiduciary Trust Company.5&Vanguard Target Retirement 2045 Fund -5666~ 6h77734,102 shares 8*(8 Vanguard Fiduciary Trust Company.8&Vanguard Target Retirement 2030 Fund -~ 8 999 7,413 shares :*(: Vanguard Fiduciary Trust Company.:&Vanguard Target Retirement 2050 Fund -~ :t;;; 5,118 shares <*(< Vanguard Fiduciary Trust Company.<&Vanguard Target Retirement 2040 Fund -~ <=== 3,425 shares >*(> Vanguard Fiduciary Trust Company.>&Vanguard Target Retirement 2005 Fund -~ >??? 3,645 sharesD lVtCi> e3Y(]-@ABCDEFGHIJKL @*(@ Vanguard Fiduciary Trust Company+@#Vanguard Target Retirement Income -~ @AAA 1,246 shares B*BFayez Sarofim & Co.,B$Sarofim Equity Fund - 205,996 shares~ BiN C*)C!Pioneer Natural Resources Company/C'Pioneer Stock Investment Fund - 507,756~ CRDDDunits E*%EParticipants loans receivable/E'Interest rates range from 5.0% to 9.25%~ EZDFFFFGGGG$ 196,911,822HI$J____________________________1K)Created by Morningstar Document Research.0L(http://documentresearch.morningstar.com/EZuLh\P(=PF0*8X> @LLKKJJ l  s dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } } } -     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Larry N. Paulsen   Larry N. Paulsen  - %Chairman of Pioneer Natural Resources    USA, Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3h;=PF0*8X> @ l  P{ dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Richard P. Dealy   Richard P. Dealy  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3e==PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Mark H. Kleinman   Mark H. Kleinman  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3e==PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (5)!Schedule H Line 4i ndash Sc (6)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Kerry D. Scott   Kerry D. Scott  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3iA=PF0*8X> @ l  \ dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (6)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Kevin J. Schepel   Kevin J. Schepel  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3e==PF0*8X> @ l   dMbP?_*+%,&٭e2?'٭e2?(٭e2?)٭e2?",D/??!With Report of Independent Regi!With Report of Independent (1)!With Report of Independent (2)Pioneer Stock Investment FundPioneer Stock Investment (1)Pioneer Stock Investment (2)Pioneer Stock Investment (3)!Schedule H Line 4i ndash Schedu!Schedule H Line 4i ndash Sc (1)!Schedule H Line 4i ndash Sc (2)!Schedule H Line 4i ndash Sc (3)!Schedule H Line 4i ndash Sc (4)!Schedule H Line 4i ndash Sc (5)U } } } 0     $PIONEER NATURAL RESOURCES CO 11-K 06/27/2008KCSchedule H; Line 4i ndash; Schedule of Assets (Held At End Of Year)Date: June 27, 2008 By:/s/ Susan A. Spratlen   Susan A. Spratlen  0 (Member of Pioneer Natural Resources USA,   Inc.  * "401(k) and Matching Plan Committee$____________________________1)Created by Morningstar Document Research.0(http://documentresearch.morningstar.com/(TWK?3c;=PF0*8X> @ Root Entry FBook    !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLM