SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
 
SCHEDULE 13G
 
Under the Securities Exchange Act of 1934
(Amendment No. )*
 

Rubicon Technology, Inc.

(Name of Issuer)
 

Common Stock, par value $0.001

(Title of Class of Securities)
 

78112T107

(CUSIP Number)
 

December 31, 2015

(Date of Event Which Requires Filing of This Statement)
 
 
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
 
ý Rule 13d-1(b)
¨ Rule 13d-1(c)
¨ Rule 13d-1(d)
 
(Page 1 of 8 Pages)

 

______________________________

*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 the disclosures provided in a prior cover page.

The information required in 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).

 

CUSIP No. 78112T10713GPage 2 of 8 Pages

 

1

NAME OF REPORTING PERSON

Ecofin Ltd.

 

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

United Kingdom

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

845,072 shares of Common Stock*

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

845,072 shares of Common Stock*

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

845,072 shares of Common Stock*

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

3.2%*

12

TYPE OF REPORTING PERSON

IA; OO

         

 

* Represents beneficial ownership as of April 6, 2016. As of December 31, 2015 the Reporting Person may have been deemed to beneficially own 1,511,716 shares of Common Stock, representing 5.8% of the outstanding Common Stock of the Issuer as of such time.

 

CUSIP No. 78112T10713GPage 3 of 8 Pages

 

1

NAME OF REPORTING PERSON

Bernard Lambilliotte

 

2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) ¨

3 SEC USE ONLY
4

CITIZENSHIP OR PLACE OF ORGANIZATION

Belgium

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:
5

SOLE VOTING POWER

0

6

SHARED VOTING POWER

845,072 shares of Common Stock*

7

SOLE DISPOSITIVE POWER

0

8

SHARED DISPOSITIVE POWER

845,072 shares of Common Stock*

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

845,072 shares of Common Stock*

10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES ¨
11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

3.2 %*

12

TYPE OF REPORTING PERSON

HC; IN

         

 

* Represents beneficial ownership as of April 6, 2016. As of December 31, 2015 the Reporting Person may have been deemed to beneficially own 1,511,716 shares of Common Stock, representing 5.8% of the outstanding Common Stock of the Issuer as of such time.

 

 

CUSIP No. 78112T10713GPage 4 of 8 Pages

 

Item 1(a). NAME OF ISSUER
  Rubicon Technology, Inc. (the “Issuer”)
   

 

Item 1(b). ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES
 

900 East Green Street

Bensenville, Illinois 60106

   

 

Item 2(a).

NAME OF PERSON FILING
 

This statement is filed by:

 

Ecofin Ltd., a company organized under the laws of the United Kingdom, is an investment management firm wholly owned by Ecofin Holdings Ltd. with respect to the Common Stock held by certain funds to which Ecofin Ltd. serves as investment manager (the "Ecofin Funds"); and

 

Bernard Lambilliotte (“Mr. Lambilliotte”), the Principal Investment Officer of Ecofin Ltd. and the controlling shareholder of Ecofin Holdings Ltd., with respect to the Common Stock held by the Ecofin Funds .

 

The foregoing persons are hereinafter sometimes collectively referred to as the “Reporting Persons”. Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party.

 

The filing of this statement should not be construed as an admission that any of the Reporting Persons is, for the purposes of Section 13 of the Act, the beneficial owner of the Common Stock reported herein.

   

 

Item 2(b). ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE
  The address of the business office of each of the Reporting Persons is 15 Buckingham Street, London, WC2N 6DU, United Kingdom.
   

 

  Item 2(c). CITIZENSHIP  
    Ecofin Ltd. is a company organized under the laws of the United Kingdom.  Mr. Lambilliotte is a Belgian citizen.  

 

Item 2(d).

 

TITLE OF CLASS OF SECURITIES

  Common Stock par value $0.001 per share (the “Common Stock”)

 

Item 2(e). CUSIP NUMBER
  78112T107
   

 

CUSIP No. 78112T10713GPage 5 of 8 Pages

 

 

Item 3. IF THIS STATEMENT IS FILED PURSUANT TO Rules 13d-1(b), OR 13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:

 

  (a) ¨ Broker or dealer registered under Section 15 of the Act;
  (b) ¨ Bank as defined in Section 3(a)(6) of the Act;
  (c) ¨ Insurance company as defined in Section 3(a)(19) of the Act;
  (d) ¨ Investment company registered under Section 8 of the Investment Company Act of 1940;
  (e) ý An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
  (f) ¨

An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

 

  (g) ý A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
  (h) ¨

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;

 

  (i) ¨

A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;

 

  (j) ¨ A non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J);
  (k) ¨ Group, in accordance with Rule 13d-1(b)(1)(ii)(K).

 

 

If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please specify the type of institution: ____________________

 

 

 

CUSIP No. 78112T10713GPage 6 of 8 Pages

Item 4. OWNERSHIP

 

 

 

 

 

 

 

 

 

 

 

 

 

The information required by Items 4(a) – (c) is set forth in Rows (5) – (11) of the cover page for each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person. The percentage set forth in Row (11) of the cover page for each Reporting Person is based on a total of 26,722,958 shares of Common Stock reported to be outstanding by the Issuer as of March 9, 2016 in its Annual Report on Form 10-K for the fiscal year ended December 31, 2015 filed with the Securities and Exchange Commission on March 14, 2016.

 

On the date of the event which requires the filing of this Schedule 13G, each of the Reporting Persons may have been deemed to be the beneficial owner of 1,511,716 shares of Common Stock representing 5.8% of the outstanding shares of Common Stock as of such time, based on a total of 26,203,535 shares of Common Stock reported to be outstanding by the Issuer as of November 4, 2015 in its Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2015 filed with the Securities and Exchange Commisson on November 9, 2015.

  

Item 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS
   
  If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following ý

 

Item 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
  See Item 2.

 

Item 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON
  Not applicable.

 

Item 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
  Not applicable.

 

Item 9. NOTICE OF DISSOLUTION OF GROUP
  Not applicable.

 

Item 10. CERTIFICATION

 

  Each of the Reporting Persons hereby makes the following certification:
   
  By signing below each Reporting Person certifies that, to the best of his or its knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

 

CUSIP No. 78112T10713GPage 7 of 8 Pages

SIGNATURES

After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

DATE: April 6, 2016

 

     
        
      By:  /s/ Bernard Lambilliotte
      Bernard Lambilliotte., individually and as
      Principal Investment Officer of Ecofin Ltd.
     
     
     

 

CUSIP No. 78112T10713GPage 8 of 8 Pages

EXHIBIT 1

JOINT FILING AGREEMENT
PURSUANT TO RULE 13d-1(k)

The undersigned acknowledge and agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13G shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements. 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 herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate.

DATE: April 6, 2016

 

     
        
      By:  /s/ Bernard Lambilliotte
      Bernard Lambilliotte., individuallyand as
      Principal Investment Officer of Ecofin Ltd.