SEC FORM 13F-HR

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 COVER PAGE

OMB APPROVAL
OMB Number:3235-0006
Expires:Oct 31, 2018
Estimated average burden
hours per response:23.8

Report for the Calendar Year or Quarter Ended:12-31-2013
Check here if Amendment  Amendment Number:
This Amendment (Check only one.):  is a restatement.
  adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name:COWEN GROUP, INC.
Address:599 LEXINGTON AVENUE, 20TH FLOOR
NEW YORK, NY  10022
Form 13F File Number:028-14571

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:
Name:Owen Littman
Title:General Counsel
Phone:212-201-4841
Signature, Place, and Date of Signing:
/s/ Owen LittmanNew YorkNY02-13-2014
[Signature][City, State][Date]
Report Type (Check only one.):
X13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.)
  13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).)
  13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)
Form 13F Summary Page
Report Summary:
Number of Other Included Managers:3
Form 13F Information Table Entry Total:226
Form 13F Information Table Value Total:594,922
(thousands)
List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.
[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]
No.Form 13F File NumberName
1028-10674RAMIUS ADVISORS LLC
2028-14361Ramius Alternative Solutions LLC
3028-04125COWEN & COMPANY, LLC

SEC FORM 13-F Information Table

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
Expires:Oct 31, 2018
Estimated average burden
hours per response:23.8

COLUMN 1COLUMN 2COLUMN 3COLUMN 4COLUMN 5COLUMN 6COLUMN 7COLUMN 8
VALUESHRS ORSH/PUT/INVESTMENTOTHERVOTING AUTHORITY
NAME OF ISSUERTITLE OF CLASSCUSIP(x$1000)PRN AMTPRNCALLDISCRETIONMANAGERSOLESHAREDNONE
ACHILLION PHARMACEUTICALS INCOM00448Q2015015,000SH DFND115,00000
ACHILLION PHARMACEUTICALS INCOM00448Q201332100,000SHCallDFND3100,00000
ACI WORLDWIDE INCCOM0044981012,47738,100SH DFND238,10000
ADOBE SYS INCCOM00724F1012,58143,100SH DFND243,10000
AIR PRODS & CHEMS INCCOM0091581062,45922,000SH DFND222,00000
AIR PRODS & CHEMS INCCOM0091581062,53722,700SH DFND322,70000
AIR PRODS & CHEMS INCCOM0091581062,53722,700SHPutDFND322,70000
AKAMAI TECHNOLOGIES INCCOM00971T1012,50153,000SH DFND253,00000
ALCOA INCCOM01381710139337,000SHCallDFND337,00000
ALLISON TRANSMISSION HLDGS ICOM01973R10147217,092SH DFND117,09200
AMERICAN AIRLS GROUP INCCOM02376R1021,40155,500SHCallDFND155,50000
AMERICAN AIRLS GROUP INCCOM02376R1021,96977,985SH DFND177,98500
AMERICAN RLTY CAP PPTYS INCCOM02917T10429422,900SHCallDFND322,90000
ANTARES PHARMA INCCOM0366421066715,000SH DFND115,00000
AOL INCCOM00184X1052,09344,900SH DFND344,90000
APPLIED MATLS INCCOM038222105885,000SH DFND35,00000
APPLIED MATLS INCCOM0382221057,358416,200SHCallDFND1416,20000
ARENA PHARMACEUTICALS INCCOM0400471025910,000SH DFND110,00000
ARIAD PHARMACEUTICALS INCCOM04033A10010215,000SH DFND115,00000
ASHLAND INC NEWCOM0442091042,18022,468SH DFND122,46800
ASHLAND INC NEWCOM0442091042,47525,500SH DFND225,50000
ASHLAND INC NEWCOM0442091045,03651,900SHPutDFND151,90000
BAKER HUGHES INCCOM0572241072,48144,900SH DFND244,90000
BARRICK GOLD CORPCOM06790110844125,000SH DFND125,00000
BEAM INCCOM0737301032,38235,000SH DFND235,00000
BLUEBIRD BIO INCCOM09609G1003,330158,709SH DFND1158,70900
BOARDWALK PIPELINE PARTNERSUT LTD PARTNER09662710471728,100SH DFND128,10000
BOB EVANS FARMS INCCOM0967611011,60131,643SH DFND131,64300
BROCADE COMMUNICATIONS SYS ICOM NEW1116213062,477279,400SH DFND2279,40000
BUCKEYE PARTNERS L PUNIT LTD PARTN1182301011,22517,250SH DFND117,25000
BURGER KING WORLDWIDE INCCOM1212201072,569112,400SH DFND2112,40000
CACI INTL INCCL A1271903042,40932,900SH DFND232,90000
CANADIAN PAC RY LTDCOM13645T1002,37615,700SH DFND215,70000
CAPITAL ONE FINL CORPCOM14040H1053835,000SH DFND15,00000
CAPITAL SR LIVING CORPCOM14047510424010,000SHPutDFND310,00000
CBS CORP NEWCL B1248572022,56940,300SH DFND240,30000
CEMPRA INCCOM15130J10924820,000SH DFND120,00000
CHICOS FAS INCCOM1686151022,376126,100SH DFND2126,10000
CISCO SYS INCCOM17275R10245720,383SH DFND320,38300
CISCO SYS INCCOM17275R1023,813170,000SHPutDFND3170,00000
COBALT INTL ENERGY INCCOM19075F10662938,200SHCallDFND338,20000
COLE REAL ESTATE INVTS INCCOM19329V1051,841131,100SH DFND1131,10000
COMMONWEALTH REITCOM SH BEN INT2032331012,434104,400SH DFND2104,40000
COMMONWEALTH REITCOM SH BEN INT203233101278SH DFND37800
COMMUNITY HEALTH SYS INC NEWCOM20366810839999SH DFND399900
COMMUNITY HEALTH SYS INC NEWCOM20366810871918,300SH DFND118,30000
COMMUNITY HEALTH SYS INC NEWCOM2036681083,18481,100SHCallDFND181,10000
COMPUWARE CORPCOM2056381092,879256,800SHCallDFND1256,80000
COMPUWARE CORPCOM2056381093,051272,208SH DFND1272,20800
COWEN GROUP INC NEWCL A22362210116,8774,316,490SH DFND14,316,49000
CRESTWOOD MIDSTREAM PARTNERSUNIT LTD PARTNER22637810781232,624SH DFND132,62400
CUBIST PHARMACEUTICALS INCCOM2296781072073,000SH DFND13,00000
CYPRESS SEMICONDUCTOR CORPCOM23280610926325,000SHPutDFND325,00000
CYPRESS SEMICONDUCTOR CORPCOM23280610955152,500SHCallDFND352,50000
EBAY INCCOM27864210387315,916SH DFND115,91600
EDWARDS GROUP LTDSPONSORED ADR2817361081,174115,344SH DFND1115,34400
ENERGY TRANSFER EQUITY L PCOM UT LTD PTN29273V1001,73121,175SH DFND121,17500
ENTERPRISE PRODS PARTNERS LCOM29379210798614,875SH DFND114,87500
EQUINIX INCCOM NEW29444U5022,85316,080SH DFND116,08000
EXXON MOBIL CORPCOM30231G1023012,971SH DFND12,97100
F M C CORPCOM NEW3024913031,96226,000SHCallDFND326,00000
FAMILY DLR STORES INCCOM3070001091953,000SH DFND33,00000
FAMILY DLR STORES INCCOM30700010965010,000SHCallDFND310,00000
FAMILY DLR STORES INCCOM30700010965010,000SHPutDFND310,00000
FAMILY DLR STORES INCCOM3070001092,36536,400SH DFND236,40000
FEDERAL SIGNAL CORPCOM31385510867045,708SH DFND145,70800
FIDELITY NATIONAL FINANCIALCL A31620R10514,333441,700SHCallDFND1441,70000
FORTRESS PAPER LTD-CL ACS34958R1011,114280,328SH DFND1280,32800
GENERAL GROWTH PPTYS INC NEWCOM3700231032,294114,300SH DFND2114,30000
GENESIS ENERGY L PUNIT LTD PARTN3719271043947,500SH DFND17,50000
GERON CORPCOM3741631035912,500SH DFND112,50000
GOOGLE INCCL A38259P5081,4571,300SH DFND11,30000
HALLIBURTON COCOM4062161017,993157,500SHCallDFND3157,50000
HARMAN INTL INDS INCCOM4130861092,39829,300SH DFND229,30000
HEALTH MGMT ASSOC INC NEWCL A42193310246235,300SHCallDFND335,30000
HEALTH MGMT ASSOC INC NEWCL A4219331021,391106,200SHPutDFND1106,20000
HERBALIFE LTDCOM USD SHSG4412G10183210,575SH DFND110,57500
HEWLETT PACKARD COCOM4282361032,44387,300SH DFND287,30000
HOLOGIC INCCOM43644010150322,499SH DFND122,49900
HOUSTON AMERN ENERGY CORPCOM44183U1001038,000SH DFND138,00000
ILLINOIS TOOL WKS INCCOM4523081092,51429,900SH DFND229,90000
IMMUNOGEN INCCOM45253H1011,12576,658SH DFND376,65800
IMMUNOGEN INCCOM45253H1011,32090,000SHPutDFND390,00000
INGERSOLL-RAND PLCSHSG477911012,59342,100SH DFND242,10000
INTERNATIONAL BUSINESS MACHSCOM4592001018444,500SH DFND14,50000
ISHARESMSCI CDA ETF46428650929210,000SH DFND110,00000
ISHARESRUSSELL 2000 ETF46428765559,872519,000SHPutDFND1519,00000
JOHNSON & JOHNSONCOM4781601041651,800SH DFND31,80000
JOHNSON & JOHNSONCOM4781601041,83220,000SHPutDFND320,00000
KRAFT FOODS GROUP INCCOM50076Q1061,14321,200SH DFND321,20000
KRAFT FOODS GROUP INCCOM50076Q1061,14321,200SHPutDFND321,20000
LAMAR ADVERTISING COCL A5128151013,58768,645SH DFND168,64500
LAMAR ADVERTISING COCL A51281510115,508296,800SHPutDFND1296,80000
LAMAR ADVERTISING COCL A51281510118,001344,500SHCallDFND1344,50000
LEAP WIRELESS INTL INCCOM NEW52186330811,656669,900SHPutDFND1669,90000
LEAR CORPCOM NEW5218652042,37229,300SH DFND229,30000
LENDER PROCESSING SVCS INCCOM52602E10296425,787SH DFND125,78700
LIFE TECHNOLOGIES CORPCOM53217V1095,21568,800SHCallDFND368,80000
LIFE TECHNOLOGIES CORPCOM53217V10933,882446,989SH DFND1446,98900
LINN ENERGY LLCUNIT LTD LIAB5360201004,899159,100SHCallDFND1159,10000
LINNCO LLCCOMSHS LTD INT53578210601SH DFND3100
LINNCO LLCCOMSHS LTD INT5357821061,68554,700SHPutDFND154,70000
LORAL SPACE & COMMUNICATNS ICOM5438811065356,600SHCallDFND36,60000
LORAL SPACE & COMMUNICATNS ICOM54388110685010,500SHPutDFND310,50000
LORAL SPACE & COMMUNICATNS ICOM5438811063,80647,000SH DFND347,00000
LSI CORPORATIONCOM50216110214312,994SH DFND312,99400
LYONDELLBASELL INDUSTRIES NSHS - A -N537451002,00725,000SHPutDFND325,00000
LYONDELLBASELL INDUSTRIES NSHS - A -N537451009,930123,700SHCallDFND3123,70000
MAGELLAN MIDSTREAM PRTNRS LPCOM UNIT RP LP5590801061,76927,960SH DFND127,96000
MANNKIND CORPCOM56400P20112524,000SH DFND324,00000
MCKESSON CORPCOM58155Q1032421,500SH DFND11,50000
MEDASSETS INCCOM5840451082,119106,859SH DFND2106,85900
MENS WEARHOUSE INCCOM58711810061212,000SHCallDFND312,00000
MICROSOFT CORPCOM5949181042,34262,600SH DFND262,60000
MONDELEZ INTL INCCL A6092071052,43969,100SH DFND269,10000
MOTOROLA SOLUTIONS INCCOM NEW6200763072,46436,500SH DFND236,50000
MYLAN INCCOM6285301073,03870,000SHPutDFND370,00000
MYRIAD GENETICS INCCOM62855J104633,000SH DFND33,00000
MYRIAD GENETICS INCCOM62855J10442020,000SHPutDFND320,00000
NABORS INDUSTRIES LTDSHSG6359F10367939,968SH DFND139,96800
NCR CORP NEWCOM62886E10851114,994SH DFND114,99400
NCR CORP NEWCOM62886E1082,51073,700SH DFND273,70000
NEUROCRINE BIOSCIENCES INCCOM64125C1099310,000SHCallDFND310,00000
NII HLDGS INCCL B NEW62913F2010100SH DFND310000
NII HLDGS INCCL B NEW62913F201388140,900SHCallDFND3140,90000
NII HLDGS INCCL B NEW62913F201792288,178SH DFND1288,17800
NORTHWEST PIPE COCOM6677461011,95751,820SH DFND151,82000
NUANCE COMMUNICATIONS INCCOM67020Y1001,51599,700SHCallDFND199,70000
NUANCE COMMUNICATIONS INCCOM67020Y1002,749180,827SH DFND1180,82700
NUANCE COMMUNICATIONS INCCOM67020Y10015210,000SH DFND310,00000
NUPATHE INCCOM67059M100420128,492SH DFND1128,49200
OIL STS INTL INCCOM6780261052,04920,147SH DFND120,14700
OIL STS INTL INCCOM6780261052,40123,600SH DFND223,60000
OLIN CORPCOM PAR $16806652051,01035,000SHCallDFND335,00000
OMNICOM GROUP INCCOM68191910617,403234,006SH DFND1234,00600
ONCOTHYREON INCCOM682324108616350,000SH DFND1350,00000
ONEOK PARTNERS LPUNIT LTD PARTN68268N10362211,815SH DFND111,81500
OUTERWALL INCCOM6900701071,00414,922SH DFND114,92200
OWENS ILL INCCOM NEW6907684032,54871,200SH DFND271,20000
PACTERA TECHNOLOGY INTL LTDSPONSORED ADR695255109718102,500SHPutDFND1102,50000
PARKERVISION INCCOM7013541029120,000SH DFND120,00000
PENNEY J C INCCOM7081601062,814307,500SHCallDFND1307,50000
PENNEY J C INCCOM70816010671277,800SHPutDFND177,80000
PEPSICO INCCOM7134481082,36428,500SH DFND228,50000
PLAINS ALL AMERN PIPELINE LUNIT LTD PARTN7265031051,09121,070SH DFND121,07000
POLYCOM INCCOM73172K10459052,500SH DFND352,50000
POLYCOM INCCOM73172K10463456,500SHPutDFND356,50000
POWERSHARES ETF TRUST IISENIOR LN PORT73936Q76913,211530,803SH DFND2530,80300
PROGRESSIVE WASTE SOLUTIONSCOM74339G1011,97979,958SH DFND279,95800
PROSHARES TR IIULTRASHORT YEN N74347W56978011,000SH DFND111,00000
PVR PARTNERS L PCOM UNIT REPTG L6936651012,48292,523SH DFND192,52300
QUESTCOR PHARMACEUTICALS INCCOM74835Y1014798,800SHCallDFND38,80000
RAYTHEON COCOM NEW75511150794310,400SH DFND310,40000
RAYTHEON COCOM NEW75511150794310,400SHPutDFND310,40000
REGENCY ENERGY PARTNERS L PCOM UNITS L P75885Y10726310,000SH DFND110,00000
REGIONS FINL CORP NEWCOM7591EP10058459,000SHCallDFND359,00000
RIVERBED TECHNOLOGY INCCOM76857310746225,558SH DFND125,55800
RLJ ENTMT INCCOM74965F1046513,503SH DFND113,50300
ROCKWELL COLLINS INCCOM7743411012,43232,900SH DFND232,90000
ROCKWOOD HLDGS INCCOM7744151032733,800SHCallDFND33,80000
SAFEWAY INCCOM NEW78651420881425,000SHCallDFND125,00000
SAFEWAY INCCOM NEW7865142084,589140,900SHPutDFND1140,90000
SALESFORCE COM INCCOM79466L3022765,000SH DFND35,00000
SALESFORCE COM INCCOM79466L3023867,000SHPutDFND37,00000
SANCHEZ ENERGY CORPCOM79970Y10526610,857SH DFND110,85700
SANTARUS INCCOM80281730463920,000SH DFND320,00000
SCHWAB CHARLES CORP NEWCOM8085131051,30450,150SH DFND150,15000
SCIENCE APPLICATNS INTL CP NCOM80862510766120,000SH DFND120,00000
SCIENTIFIC GAMES CORPCL A80874P1094,735279,701SH DFND1279,70100
SEALED AIR CORP NEWCOM81211K1001,27737,500SHCallDFND337,50000
SEATTLE GENETICS INCCOM812578102802,000SH DFND32,00000
SEATTLE GENETICS INCCOM8125781021,00925,300SHPutDFND325,30000
SERVICE CORP INTLCOM8175651041,73195,479SH DFND195,47900
SIGA TECHNOLOGIES INCCOM826917106686209,654SH DFND1209,65400
SLM CORPCOM78442P1066200SHPutDFND320000
SLM CORPCOM78442P10623,915910,000SHCallDFND3910,00000
SOTHEBYSCOM8358981072,45346,100SH DFND246,10000
SPDR S&P 500 ETF TRTR UNIT78462F1039054,900SH DFND14,90000
SPDR S&P 500 ETF TRTR UNIT78462F10331,582171,000SHPutDFND1171,00000
SPDR SERIES TRUSTBRC HGH YLD BD78464A4171,08526,750SH DFND126,75000
SPRINT CORPCOM SER 185207U10554850,989SH DFND150,98900
SPX CORPCOM7846351042,52025,300SH DFND225,30000
STERLING BANCORP DELCOM85917A10069551,960SH DFND151,96000
SUBURBAN PROPANE PARTNERS LUNIT LTD PARTN86448210467114,297SH DFND114,29700
SUNEDISON INCCOM86732Y1091,355103,900SHPutDFND3103,90000
SUNEDISON INCCOM86732Y10930123,000SHCallDFND323,00000
SUNEDISON INCCOM86732Y1091,25396,000SH DFND396,00000
SUNESIS PHARMACEUTICALS INCCOM NEW8673286013,299696,075SH DFND3696,07500
SUNOCO LOGISTICS PRTNRS L PCOM UNITS86764L1081,22716,259SH DFND116,25900
SYSCO CORPCOM8718291075,429150,400SHCallDFND1150,40000
TETRAPHASE PHARMACEUTICALS ICOM88165N10520315,000SH DFND115,00000
THE ADT CORPORATIONCOM00101J1063649,000SH DFND39,00000
THE ADT CORPORATIONCOM00101J1062,02450,000SHCallDFND350,00000
THE ADT CORPORATIONCOM00101J1062,40059,300SH DFND259,30000
THERAVANCE INCCOM88338T1041,42640,005SH DFND140,00500
THERMO FISHER SCIENTIFIC INCCOM8835561022,59423,300SH DFND223,30000
TIME WARNER CABLE INCCOM88732J2077605,612SH DFND15,61200
TIME WARNER CABLE INCCOM88732J2072,33117,200SHPutDFND117,20000
TIMKEN COCOM88738910487415,875SH DFND115,87500
T-MOBILE US INCCOM87259010454216,119SH DFND116,11900
TRANSOCEAN LTDREG SHSH8817H10097219,659SH DFND119,65900
TRANSOCEAN LTDREG SHSH8817H1005,174104,700SHCallDFND1104,70000
UNITED RENTALS INCCOM9113631092,62733,700SH DFND233,70000
UNITEDHEALTH GROUP INCCOM91324P1022863,800SH DFND33,80000
UNITEDHEALTH GROUP INCCOM91324P1022863,800SHPutDFND33,80000
UTI WORLDWIDE INCORDG872101032,378135,430SH DFND2135,43000
VAIL RESORTS INCCOM91879Q1092,40031,900SH DFND231,90000
VALEANT PHARMACEUTICALS INTLCOM91911K1022,59522,100SH DFND222,10000
VANDA PHARMACEUTICALS INCCOM92165910831025,000SH DFND125,00000
VERTEX PHARMACEUTICALS INCCOM92532F1001,85825,000SHPutDFND325,00000
VERTEX PHARMACEUTICALS INCCOM92532F1003725,000SHCallDFND35,00000
VERTEX PHARMACEUTICALS INCCOM92532F1007069,500SH DFND39,50000
VIRNETX HLDG CORPCOM92823T1084,778246,157SH DFND1246,15700
VIROPHARMA INCCOM92824110899720,000SH DFND120,00000
VIROPHARMA INCCOM9282411082,55251,200SHPutDFND151,20000
VIVUS INCCOM9285511001,432157,738SH DFND1157,73800
VIVUS INCCOM9285511002,543280,000SHCallDFND3280,00000
VMWARE INCCL A COM9285634026,09167,900SHPutDFND367,90000
WAL-MART STORES INCCOM9311421036398,125SH DFND18,12500
WAL-MART STORES INCCOM9311421033,93550,000SHCallDFND350,00000
WALTER INVT MGMT CORPCOM93317W10240111,335SH DFND111,33500
WENDYS COCOM95058W1002,454281,400SH DFND2281,40000
WILLIAMS COS INC DELCOM96945710048212,500SH DFND112,50000
WILLIAMS COS INC DELCOM9694571002,64668,600SH DFND268,60000
XYLEM INCCOM98419M10065418,900SHCallDFND318,90000
YUM BRANDS INCCOM9884981014,15855,000SHCallDFND355,00000