SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 --------------------- SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a) (Amendment No. 4 (Exiting))1 AMERICAN MEDICAL SECURITY GROUP, INC. -------------------------- (Name of Issuer) Common Stock, No Par Value ----------------------------- (Title of Class of Securities) 02744P101 ------------ (CUSIP Number) Scott B. Bernstein, Esq. Caxton Associates, L.L.C. 731 Alexander Road, Bldg. 2 Princeton, New Jersey 08540 (609) 419-1800 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) February 5, 2002 ------------------------------------ Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1 (e), 13d-1 (f), or 13d-1 (g), check the following box o. Note. Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) for other parties to whom copies are to be sent. (Continued on following pages) (Page 1 of 10 Pages) _________________ 1 The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). SCHEDULE 13D CUSIP NO. 02744P101 1 NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY) Caxton International Limited ----------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |_| ----------------------------------------------------------------------------- 3 SEC USE ONLY ----------------------------------------------------------------------------- 4 SOURCE OF FUNDS* WC ----------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) |_| ----------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION British Virgin Islands ----------------------------------------------------------------------------- NUMBER OF 7 SOLE VOTING POWER 0 SHARES ------------------------------------------------------------- BENEFICIALLY 8 SHARED VOTING POWER 649,300 OWNED BY ------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER 0 REPORTING ------------------------------------------------------------- PERSON 10 SHARED DISPOSITIVE POWER 649,300 WITH ------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 649,300 ----------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* ----------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.7% ----------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* CO ----------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! CUSIP NO. 02744P101 1 NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY) Caxton Associates, L.L.C. ----------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |_| ----------------------------------------------------------------------------- 3 SEC USE ONLY ----------------------------------------------------------------------------- 4 SOURCE OF FUNDS* Not Applicable ----------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) |_| ----------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION Delaware ----------------------------------------------------------------------------- NUMBER OF 7 SOLE VOTING POWER 0 SHARES ------------------------------------------------------------- BENEFICIALLY 8 SHARED VOTING POWER 649,300 OWNED BY ------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER 0 REPORTING ------------------------------------------------------------- PERSON 10 SHARED DISPOSITIVE POWER 649,300 WITH ------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 649,300 ----------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* ----------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.7% ----------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* CO ----------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! SCHEDULE 13D CUSIP NO. 02744P101 1 NAME OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY) Bruce S. Kovner ----------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |_| ----------------------------------------------------------------------------- 3 SEC USE ONLY ----------------------------------------------------------------------------- 4 SOURCE OF FUNDS* Not Applicable ----------------------------------------------------------------------------- 5 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e) |_| ----------------------------------------------------------------------------- 6 CITIZENSHIP OR PLACE OF ORGANIZATION United States ----------------------------------------------------------------------------- NUMBER OF 7 SOLE VOTING POWER 0 SHARES ------------------------------------------------------------- BENEFICIALLY 8 SHARED VOTING POWER 649,300 OWNED BY ------------------------------------------------------------- EACH 9 SOLE DISPOSITIVE POWER 0 REPORTING ------------------------------------------------------------- PERSON 10 SHARED DISPOSITIVE POWER 649,300 WITH ------------------------------------------------------------- 11 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 649,300 ----------------------------------------------------------------------------- 12 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES* ----------------------------------------------------------------------------- 13 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.7% ----------------------------------------------------------------------------- 14 TYPE OF REPORTING PERSON* IN ----------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! This Amendment 4 to Schedule 13D relates to the Common Stock, no par Value (the "Common Stock"), of American Medical Security Group, Inc., a Wisconsin corporation (the "Company"), 3100 AMS Blvd., Green Bay, WI 54313. Item 5. Interest in Securities of the Issuer. The first paragraph of subparagraph (a) of Item 5 of the Schedule D is hereby amended by replacing said paragraph with the following paragraph: (a) Caxton International beneficially owns 649,300 shares of Common Stock, representing approximately 4.7% of the total shares of Common Stock issued and outstanding. The decrease in beneficial ownership from the date of Amendment No. 3 to Schedule 13D filed August 23, 2001 is a result of Caxton International's net sale of Common Stock as set forth in Schedule A. Subparagraph (c) of Item 5 of the Schedule 13D is hereby amended by adding the following sentence: (c) Caxton International Limited acquired additional shares and/or sold shares of Common Stock in a series of open market transactions effected primarily with independent brokers and, to a lesser extent, directly with market makers utilizing the NASDAQ System, between August 23, 2001 and February 12, 2002. See Schedule A for disclosure of (1) the date, (2) the price and (3) the amount of shares purchased and/or sold by Caxton International during the past 60 days. After reasonable inquiry and to the best of the undersigned's knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct. February 12, 2002 CAXTON INTERNATIONAL LIMITED By:/s/Joseph Kelly Name: Joseph Kelly Title: Vice President & Treasurer By:/s/Maxwell Quin Name: Maxwell Quin Title: Vice President & Secretary CAXTON ASSOCIATES, L.L.C. By:/s/Scott B. Bernstein Name: Scott B. Bernstein Title: Secretary /s/Bruce S. Kovner Bruce S. Kovner, by Scott B. Bernstein as Attorney-in-Fact Schedule A Caxton International Limited No of Shares Price Per Share Trade Date Purchased (Sold) (Excluding Commission) 13-DEC-01 10,200 10.6627 13-DEC-01 6,200 10.6403 14-DEC-01 (100) 10.7200 14-DEC-01 2,000 10.6445 18-DEC-01 (2,000) 11.2625 19-DEC-01 (1,000) 11.4250 21-DEC-01 2,000 11.3500 24-DEC-01 5,000 11.3910 26-DEC-01 (1,600) 11.6000 27-DEC-01 (11,000) 11.8173 28-DEC-01 2000 12.0000 31-DEC-01 400 11.9500 07-JAN-02 (14,500) 11.7500 18-JAN-02 (2,300) 12.0500 30-JAN-02 2,000 11.1000 05-FEB-02 (33,500) 12.8503 07-FEB-02 (5,000) 12.9590 08-FEB-02 (18,300) 13.1342 Exhibit Index Exhibit 1 - Joint Acquisition Statement Pursuant To Rule 13d-1(k)(1). Exhibit 1 JOINT ACQUISITION STATEMENT PURSUANT TO RULE 13d-1(k)(l) The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the other, except to the extent that he or it knows or has reason to believe that such information is inaccurate. Dated: February 12, 2002 CAXTON INTERNATIONAL LIMITED By:/s/Joseph Kelly Name: Joseph Kelly Title: Vice President & Treasurer By:/s/Maxwell Quin Name: Maxwell Quin Title: Vice President & Secretary CAXTON ASSOCIATES, L.L.C. By:/s/Scott B. Bernstein Name: Scott B. Bernstein Title: Secretary /s/Bruce S. Kovner Bruce S. Kovner, by Scott B. Bernstein as Attorney-in-Fact