FORM 3
        
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                       
1. Name and Address of Reporting Person * Bandera Partners LLC 2. Date of Event Requiring Statement (MM/DD/YYYY)
5/14/2020 

 3. Issuer Name and Ticker or Trading Symbol Rubicon Technology, Inc. [RBCN]
(Last)       (First)       (Middle)
50 BROAD STREET, SUITE 1820, 		 4. Relationship of Reporting Person(s) to Issuer (Check all applicable)_____ Director                          ___X___ 10% Owner
_____ Officer (give title below)        _____ Other (specify below)
(Street)
NEW YORK, NY 10004      
(City)             (State)             (Zip)
 5. If Amendment, Date Original Filed(MM/DD/YYYY)
 

 6. Individual or Joint/Group Filing(Check Applicable Line)___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock (1) 258256  I  See footnote (2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(MM/DD/YYYY)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares

Explanation of Responses:
(1)  This Form 3 is filed jointly by Bandera Partners LLC ("Bandera Partners") and Gregory Bylinsky (collectively, the "Reporting Persons"). Each of the Reporting Persons may be deemed to be a member of a Section 13(d) group that collectively beneficially owns more than 10% of the Issuer's outstanding shares of Common Stock. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein.
(2)  Bandera Partners is the investment manager of Bandera Master Fund L.P. ("Bandera Master Fund"), in whose name the shares are held. Mr. Bylinsky is a Managing Partner, Managing Director and Portfolio Manager of Bandera Partners. Bandera Master Fund has delegated to Bandera Partners the sole and exclusive authority to vote and dispose of the securities held by Bandera Master Fund. As a result, each of Bandera Partners and Mr. Bylinsky may be deemed to beneficially own the shares held by Bandera Master Fund.

Remarks:
This filing was triggered as a result of a reduction in the number of outstanding shares of Common Stock of the Issuer.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
Bandera Partners LLC
50 BROAD STREET, SUITE 1820
NEW YORK, NY 10004
X

Bylinsky Gregory
C/O BANDERA PARTNERS LLC
50 BROAD STREET, SUITE 1820
NEW YORK, NY 10004
X


Signatures
/s/ Gregory Bylinsky, Managing Director, on behalf of Bandera Partners LLC 9/14/2020
**Signature of Reporting Person Date
/s/ Gregory Bylinsky 9/14/2020
**Signature of Reporting Person Date