The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
Agilent Technologies, Inc. COM 00846U101 13,306 178,200 SH   SOLE   178,200 0 0
Advance Auto Parts, Inc. COM 00751Y106 10,790 70,000 SH   SOLE   70,000 0 0
Apple Inc. COM 037833100 57,852 292,300 SH   SOLE   292,300 0 0
Abbott Laboratories COM 002824100 28,829 342,800 SH   SOLE   342,800 0 0
Accenture plc Class A COM G1151C101 23,392 126,600 SH   SOLE   126,600 0 0
Adobe Inc. COM 00724F101 32,441 110,100 SH   SOLE   110,100 0 0
Aflac Incorporated COM 001055102 15,259 278,400 SH   SOLE   278,400 0 0
Alexion Pharmaceuticals, Inc. COM 015351109 19,215 146,700 SH   SOLE   146,700 0 0
American Tower Corporation COM 03027X100 19,484 95,300 SH   SOLE   95,300 0 0
Amazon.com, Inc. COM 023135106 78,207 41,300 SH   SOLE   41,300 0 0
Air Products and Chemicals, Inc. COM 009158106 13,152 58,100 SH   SOLE   58,100 0 0
AvalonBay Communities, Inc. COM 053484101 16,092 79,200 SH   SOLE   79,200 0 0
Broadcom Inc. COM 11135F101 17,732 61,600 SH   SOLE   61,600 0 0
American Express Company COM 025816109 24,453 198,100 SH   SOLE   198,100 0 0
Boeing Company COM 097023105 19,001 52,200 SH   SOLE   52,200 0 0
Bank of America Corp. COM 060505104 38,440 1,325,500 SH   SOLE   1,325,500 0 0
Ball Corporation COM 058498106 7,209 103,000 SH   SOLE   103,000 0 0
BP plc. Sponsored ADR COM 055622104 3,369 80,800 SH   SOLE   80,800 0 0
Berkshire Hathaway Inc. Class B COM 084670702 12,982 60,900 SH   SOLE   60,900 0 0
Comcast Corporation Class A COM 20030N101 28,251 668,200 SH   SOLE   668,200 0 0
Chipotle Mexican Grill, Inc. COM 169656105 15,830 21,600 SH   SOLE   21,600 0 0
Costco Wholesale Corporation COM 22160K105 18,577 70,300 SH   SOLE   70,300 0 0
salesforce.com, inc. COM 79466L302 21,212 139,800 SH   SOLE   139,800 0 0
Cisco Systems, Inc. COM 17275R102 28,646 523,400 SH   SOLE   523,400 0 0
Cintas Corporation COM 172908105 11,485 48,400 SH   SOLE   48,400 0 0
Corteva Inc. COM 22052L104 1,697 57,400 SH   SOLE   57,400 0 0
Chevron Corporation COM 166764100 7,641 61,400 SH   SOLE   61,400 0 0
Delta Air Lines, Inc. COM 247361702 12,269 216,200 SH   SOLE   216,200 0 0
DuPont de Nemours, Inc. COM 26614N102 4,309 57,400 SH   SOLE   57,400 0 0
Dollar General Corporation COM 256677105 18,549 137,237 SH   SOLE   137,237 0 0
Walt Disney Company COM 254687106 9,607 68,800 SH   SOLE   68,800 0 0
Dow, Inc. COM 260557103 2,830 57,400 SH   SOLE   57,400 0 0
EOG Resources, Inc. COM 26875P101 8,124 87,200 SH   SOLE   87,200 0 0
Edwards Lifesciences Corporation COM 28176E108 22,705 122,900 SH   SOLE   122,900 0 0
Exelon Corporation COM 30161N101 14,348 299,300 SH   SOLE   299,300 0 0
Diamondback Energy, Inc. COM 25278X109 8,086 74,200 SH   SOLE   74,200 0 0
Facebook, Inc. Class A COM 30303M102 17,582 91,100 SH   SOLE   91,100 0 0
Fidelity National Information Services, Inc. COM 31620M106 17,740 144,600 SH   SOLE   144,600 0 0
Fifth Third Bancorp COM 316773100 16,910 606,100 SH   SOLE   606,100 0 0
General Electric Company COM 369604103 2,588 246,500 SH   SOLE   246,500 0 0
Alphabet Inc. Class C COM 02079K107 12,103 11,197 SH   SOLE   11,197 0 0
Alphabet Inc. Class A COM 02079K305 29,669 27,400 SH   SOLE   27,400 0 0
Honeywell International Inc. COM 438516106 35,442 203,000 SH   SOLE   203,000 0 0
Intercontinental Exchange, Inc. COM 45866F104 23,977 279,000 SH   SOLE   279,000 0 0
Johnson & Johnson COM 478160104 28,538 204,900 SH   SOLE   204,900 0 0
JPMorgan Chase & Co. COM 46625H100 33,339 298,200 SH   SOLE   298,200 0 0
Coca-Cola Company COM 191216100 27,151 533,200 SH   SOLE   533,200 0 0
Kansas City Southern COM 485170302 13,327 109,400 SH   SOLE   109,400 0 0
Cheniere Energy, Inc. COM 16411R208 9,193 134,300 SH   SOLE   134,300 0 0
Lowe's Companies, Inc. COM 548661107 15,419 152,800 SH   SOLE   152,800 0 0
Lam Research Corporation COM 512807108 9,354 49,800 SH   SOLE   49,800 0 0
Mastercard Incorporated Class A COM 57636Q104 36,796 139,100 SH   SOLE   139,100 0 0
Mondelez International, Inc. Class A COM 609207105 13,179 244,500 SH   SOLE   244,500 0 0
Medtronic plc COM G5960L103 21,689 222,700 SH   SOLE   222,700 0 0
Merck & Co., Inc. COM 58933Y105 34,269 408,700 SH   SOLE   408,700 0 0
Microsoft Corporation COM 594918104 105,815 789,900 SH   SOLE   789,900 0 0
NextEra Energy, Inc. COM 65339F101 20,281 99,000 SH   SOLE   99,000 0 0
Netflix, Inc. COM 64110L106 18,476 50,300 SH   SOLE   50,300 0 0
NIKE, Inc. Class B COM 654106103 22,944 273,300 SH   SOLE   273,300 0 0
Oracle Corporation COM 68389X105 6,962 122,200 SH   SOLE   122,200 0 0
Palo Alto Networks, Inc. COM 697435105 14,548 71,400 SH   SOLE   71,400 0 0
Public Service Enterprise Group Incorporated COM 744573106 10,229 173,900 SH   SOLE   173,900 0 0
Adams Natural Resources Fund Inc. COM 00548F105 36,169 2,186,774 SH   SOLE   2,186,774 0 0
PepsiCo, Inc. COM 713448108 15,565 118,700 SH   SOLE   118,700 0 0
Pfizer Inc. COM 717081103 9,181 211,940 SH   SOLE   211,940 0 0
Procter & Gamble Company COM 742718109 12,648 115,350 SH   SOLE   115,350 0 0
Parker-Hannifin Corporation COM 701094104 17,222 101,300 SH   SOLE   101,300 0 0
Prologis, Inc. COM 74340W103 19,424 242,500 SH   SOLE   242,500 0 0
Philip Morris International Inc. COM 718172109 15,470 197,000 SH   SOLE   197,000 0 0
Royal Dutch Shell plc Class B Sponsored ADR COM 780259107 3,609 54,900 SH   SOLE   54,900 0 0
Raymond James Financial, Inc. COM 754730109 12,987 153,600 SH   SOLE   153,600 0 0
Republic Services, Inc. COM 760759100 17,631 203,500 SH   SOLE   203,500 0 0
Sherwin-Williams Company COM 824348106 11,411 24,900 SH   SOLE   24,900 0 0
SPDR S&P 500 ETF Trust COM 78462F103 8,380 28,600 SH   SOLE   28,600 0 0
AT&T Inc. COM 00206R102 28,593 853,282 SH   SOLE   853,282 0 0
Thermo Fisher Scientific Inc. COM 883556102 25,756 87,700 SH   SOLE   87,700 0 0
Total S.A. Sponsored ADR COM 89151E109 3,392 60,800 SH   SOLE   60,800 0 0
T. Rowe Price Group COM 74144T108 18,365 167,400 SH   SOLE   167,400 0 0
Travelers Companies, Inc. COM 89417E109 20,095 134,400 SH   SOLE   134,400 0 0
Tractor Supply Company COM 892356106 17,299 159,000 SH   SOLE   159,000 0 0
Texas Instruments Incorporated COM 882508104 17,914 156,100 SH   SOLE   156,100 0 0
Unilever plc Sponsored ADR COM 904767704 11,985 193,400 SH   SOLE   193,400 0 0
Ulta Beauty, Inc. COM 90384S303 16,096 46,400 SH   SOLE   46,400 0 0
UnitedHealth Group Incorporated COM 91324P102 26,548 108,800 SH   SOLE   108,800 0 0
Union Pacific Corporation COM 907818108 25,079 148,300 SH   SOLE   148,300 0 0
U.S. Bancorp COM 902973304 25,309 483,000 SH   SOLE   483,000 0 0
United Technologies Corporation COM 913017109 22,043 169,300 SH   SOLE   169,300 0 0
Visa Inc. Class A COM 92826C839 52,308 301,400 SH   SOLE   301,400 0 0
Valero Energy Corporation COM 91913Y100 9,580 111,900 SH   SOLE   111,900 0 0
Verizon Communications Inc. COM 92343V104 4,959 86,800 SH   SOLE   86,800 0 0
WEC Energy Group Inc. COM 92939U106 13,856 166,200 SH   SOLE   166,200 0 0
Wells Fargo & Company COM 949746101 2,617 55,300 SH   SOLE   55,300 0 0
Walmart Inc. COM 931142103 20,816 188,400 SH   SOLE   188,400 0 0
Health Care Select Sector SPDR Fund COM 81369Y209 13,470 145,400 SH   SOLE   145,400 0 0
Exxon Mobil Corporation COM 30231G102 12,904 168,400 SH   SOLE   168,400 0 0
Zoetis, Inc. Class A COM 98978V103 15,843 139,600 SH   SOLE   139,600 0 0
Acadia Realty Trust COM 004239109 126 4,600 SH   DFND   0 0 4,600
Advanced Drainage Systems, Inc. COM 00790R104 174 5,300 SH   DFND   0 0 5,300
Advanced Energy Industries, Inc. COM 007973100 124 2,200 SH   DFND   0 0 2,200
Aegion Corporation COM 00770F104 151 8,200 SH   DFND   0 0 8,200
AMAG Pharmaceuticals, Inc. COM 00163U106 95 9,500 SH   DFND   0 0 9,500
Amedisys, Inc. COM 023436108 121 1,000 SH   DFND   0 0 1,000
American Equity Investment Life Holding Company COM 025676206 125 4,600 SH   DFND   0 0 4,600
American Renal Associates Holdings, Inc. COM 029227105 165 22,239 SH   DFND   0 0 22,239
America's Car-Mart, Inc. COM 03062T105 155 1,800 SH   DFND   0 0 1,800
Amkor Technology, Inc. COM 031652100 95 12,800 SH   DFND   0 0 12,800
AngioDynamics, Inc. COM 03475V101 120 6,100 SH   DFND   0 0 6,100
Aspen Technology, Inc. COM 045327103 186 1,500 SH   DFND   0 0 1,500
Atkore International Group Inc. COM 047649108 147 5,700 SH   DFND   0 0 5,700
Banner Corporation COM 06652V208 162 3,000 SH   DFND   0 0 3,000
Belden Inc. COM 077454106 155 2,600 SH   DFND   0 0 2,600
BioSpecifics Technologies Corp. COM 090931106 107 1,800 SH   DFND   0 0 1,800
Black Hills Corporation COM 092113109 141 1,800 SH   DFND   0 0 1,800
Boston Beer Company, Inc. Class A COM 100557107 151 400 SH   DFND   0 0 400
Bottomline Technologies (de), Inc. COM 101388106 119 2,700 SH   DFND   0 0 2,700
Builders FirstSource, Inc. COM 12008R107 179 10,600 SH   DFND   0 0 10,600
CalAmp Corp. COM 128126109 137 11,700 SH   DFND   0 0 11,700
Cardtronics plc Class A COM G1991C105 120 4,400 SH   DFND   0 0 4,400
Carrizo Oil & Gas, Inc. COM 144577103 81 8,100 SH   DFND   0 0 8,100
Cathay General Bancorp COM 149150104 129 3,600 SH   DFND   0 0 3,600
Chemocentryx, Inc. COM 16383L106 69 7,400 SH   DFND   0 0 7,400
Cirrus Logic, Inc. COM 172755100 118 2,700 SH   DFND   0 0 2,700
CNO Financial Group, Inc. COM 12621E103 135 8,100 SH   DFND   0 0 8,100
Cogent Communications Holdings Inc. COM 19239V302 178 3,000 SH   DFND   0 0 3,000
CommVault Systems, Inc. COM 204166102 119 2,400 SH   DFND   0 0 2,400
Continental Building Products, Inc. COM 211171103 143 5,400 SH   DFND   0 0 5,400
Costamare Inc. COM Y1771G102 102 19,900 SH   DFND   0 0 19,900
Covanta Holding Corporation COM 22282E102 145 8,100 SH   DFND   0 0 8,100
CSG Systems International, Inc. COM 126349109 181 3,700 SH   DFND   0 0 3,700
CVR Energy, Inc. COM 12662P108 130 2,600 SH   DFND   0 0 2,600
CyrusOne, Inc. COM 23283R100 127 2,200 SH   DFND   0 0 2,200
Dana Incorporated COM 235825205 156 7,800 SH   DFND   0 0 7,800
Deckers Outdoor Corporation COM 243537107 194 1,100 SH   DFND   0 0 1,100
Diamond Offshore Drilling, Inc. COM 25271C102 76 8,600 SH   DFND   0 0 8,600
Dine Brands Global, Inc. COM 254423106 172 1,800 SH   DFND   0 0 1,800
Eldorado Resorts Inc. COM 28470R102 166 3,600 SH   DFND   0 0 3,600
EMCOR Group, Inc. COM 29084Q100 167 1,900 SH   DFND   0 0 1,900
Emergent BioSolutions Inc. COM 29089Q105 72 1,500 SH   DFND   0 0 1,500
Empire State Realty Trust, Inc. Class A COM 292104106 141 9,500 SH   DFND   0 0 9,500
Enanta Pharmaceuticals, Inc. COM 29251M106 84 1,000 SH   DFND   0 0 1,000
Essent Group Ltd. COM G3198U102 150 3,200 SH   DFND   0 0 3,200
Ethan Allen Interiors Inc. COM 297602104 139 6,600 SH   DFND   0 0 6,600
FB Financial Corporation COM 30257X104 161 4,400 SH   DFND   0 0 4,400
Federal Agricultural Mortgage Corporation Class C COM 313148306 131 1,800 SH   DFND   0 0 1,800
FibroGen, Inc. COM 31572Q808 81 1,800 SH   DFND   0 0 1,800
First Bancorp COM 318910106 135 3,700 SH   DFND   0 0 3,700
First Interstate BancSystem, Inc. Class A COM 32055Y201 143 3,600 SH   DFND   0 0 3,600
FirstCash, Inc. COM 33767D105 130 1,300 SH   DFND   0 0 1,300
Gray Television, Inc. COM 389375106 100 6,100 SH   DFND   0 0 6,100
Great Southern Bancorp, Inc. COM 390905107 156 2,600 SH   DFND   0 0 2,600
Greif Class A COM 397624107 117 3,600 SH   DFND   0 0 3,600
Harsco Corporation COM 415864107 159 5,800 SH   DFND   0 0 5,800
Heritage Insurance Holdings, Inc. COM 42727J102 183 11,900 SH   DFND   0 0 11,900
Herman Miller, Inc. COM 600544100 188 4,200 SH   DFND   0 0 4,200
Highwoods Properties, Inc. COM 431284108 136 3,300 SH   DFND   0 0 3,300
Horizon Therapeutics Public Limited Company COM G46188101 111 4,600 SH   DFND   0 0 4,600
Houlihan Lokey, Inc. Class A COM 441593100 129 2,900 SH   DFND   0 0 2,900
IBERIABANK Corporation COM 450828108 137 1,800 SH   DFND   0 0 1,800
IDACORP, Inc. COM 451107106 121 1,200 SH   DFND   0 0 1,200
Independent Bank Corp. COM 453836108 137 1,800 SH   DFND   0 0 1,800
Ingles Markets, Incorporated Class A COM 457030104 140 4,500 SH   DFND   0 0 4,500
Integer Holdings Corporation COM 45826H109 151 1,800 SH   DFND   0 0 1,800
Inter Parfums, Inc. COM 458334109 120 1,800 SH   DFND   0 0 1,800
j2 Global, Inc. COM 48123V102 169 1,900 SH   DFND   0 0 1,900
Kaiser Aluminum Corporation COM 483007704 146 1,500 SH   DFND   0 0 1,500
Ladder Capital Corp. Class A COM 505743104 130 7,800 SH   DFND   0 0 7,800
Lannett Company, Inc. COM 516012101 93 15,400 SH   DFND   0 0 15,400
Matador Resources Company COM 576485205 121 6,100 SH   DFND   0 0 6,100
Matrix Service Company COM 576853105 103 5,100 SH   DFND   0 0 5,100
MGIC Investment Corporation COM 552848103 124 9,400 SH   DFND   0 0 9,400
Minerals Technologies Inc. COM 603158106 96 1,800 SH   DFND   0 0 1,800
MKS Instruments, Inc. COM 55306N104 86 1,100 SH   DFND   0 0 1,100
Movado Group, Inc. COM 624580106 127 4,700 SH   DFND   0 0 4,700
National Health Investors, Inc. COM 63633D104 140 1,800 SH   DFND   0 0 1,800
National Storage Affiliates Trust COM 637870106 148 5,100 SH   DFND   0 0 5,100
Nelnet, Inc. Class A COM 64031N108 142 2,400 SH   DFND   0 0 2,400
New Relic, Inc. COM 64829B100 112 1,300 SH   DFND   0 0 1,300
NIC Inc. COM 62914B100 125 7,800 SH   DFND   0 0 7,800
NorthWestern Corporation COM 668074305 137 1,900 SH   DFND   0 0 1,900
Oasis Petroleum Inc. COM 674215108 112 19,700 SH   DFND   0 0 19,700
Orthofix Medical, Inc. COM 68752M108 137 2,600 SH   DFND   0 0 2,600
Party City Holdco, Inc. COM 702149105 97 13,300 SH   DFND   0 0 13,300
Pebblebrook Hotel Trust COM 70509V100 121 4,300 SH   DFND   0 0 4,300
Penn National Gaming, Inc. COM 707569109 110 5,700 SH   DFND   0 0 5,700
PennyMac Mortgage Investment Trust COM 70931T103 142 6,500 SH   DFND   0 0 6,500
Phibro Animal Health Corporation Class A COM 71742Q106 105 3,300 SH   DFND   0 0 3,300
PolyOne Corporation COM 73179P106 160 5,100 SH   DFND   0 0 5,100
Portland General Electric Company COM 736508847 163 3,000 SH   DFND   0 0 3,000
Progress Software Corporation COM 743312100 148 3,400 SH   DFND   0 0 3,400
QuinStreet, Inc. COM 74874Q100 174 11,000 SH   DFND   0 0 11,000
RadNet, Inc. COM 750491102 139 10,100 SH   DFND   0 0 10,100
REGENXBIO, Inc. COM 75901B107 108 2,100 SH   DFND   0 0 2,100
Repligen Corporation COM 759916109 146 1,700 SH   DFND   0 0 1,700
Rexnord Corporation COM 76169B102 160 5,300 SH   DFND   0 0 5,300
RLJ Lodging Trust COM 74965L101 124 7,000 SH   DFND   0 0 7,000
Rush Enterprises, Inc. Class A COM 781846209 124 3,400 SH   DFND   0 0 3,400
Ruth's Hospitality Group, Inc. COM 783332109 111 4,900 SH   DFND   0 0 4,900
Sanmina-SCI Corporation COM 801056102 157 5,200 SH   DFND   0 0 5,200
Schnitzer Steel Industries, Inc. Class A COM 806882106 154 5,900 SH   DFND   0 0 5,900
SeaWorld Entertainment, Inc. COM 81282V100 155 5,000 SH   DFND   0 0 5,000
Select Medical Holdings Corporation COM 81619Q105 163 10,300 SH   DFND   0 0 10,300
Sinclair Broadcast Group, Inc. Class A COM 829226109 177 3,300 SH   DFND   0 0 3,300
SkyWest, Inc. COM 830879102 164 2,700 SH   DFND   0 0 2,700
Supernus Pharmaceuticals, Inc. COM 868459108 89 2,700 SH   DFND   0 0 2,700
Syneos Health, Inc. Class A COM 87166B102 138 2,700 SH   DFND   0 0 2,700
Tailored Brands, Inc. COM 87403A107 116 20,100 SH   DFND   0 0 20,100
Tech Data Corporation COM 878237106 136 1,300 SH   DFND   0 0 1,300
Tenet Healthcare Corporation COM 88033G407 114 5,500 SH   DFND   0 0 5,500
Tetra Tech, Inc. COM 88162G103 189 2,400 SH   DFND   0 0 2,400
TriMas Corporation COM 896215209 142 4,600 SH   DFND   0 0 4,600
Trinseo SA COM L9340P101 127 3,000 SH   DFND   0 0 3,000
TrueBlue, Inc. COM 89785X101 121 5,500 SH   DFND   0 0 5,500
TTM Technologies, Inc. COM 87305R109 115 11,300 SH   DFND   0 0 11,300
United Bankshares, Inc. COM 909907107 137 3,700 SH   DFND   0 0 3,700
Univar, Inc. COM 91336L107 159 7,200 SH   DFND   0 0 7,200
Vanda Pharmaceuticals Inc. COM 921659108 42 3,000 SH   DFND   0 0 3,000
Vector Group Ltd. COM 92240M108 123 12,585 SH   DFND   0 0 12,585
Walker & Dunlop, Inc. COM 93148P102 144 2,700 SH   DFND   0 0 2,700
Wintrust Financial Corporation COM 97650W108 132 1,800 SH   DFND   0 0 1,800
Zumiez Inc. COM 989817101 183 7,000 SH   DFND   0 0 7,000