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 *

Mosaic Venture Partners II Limited Partnership

2. Date of Event Requiring Statement (MM/DD/YYYY)
4/3/2014 

3. Issuer Name and Ticker or Trading Symbol

Five9, Inc. [FIVN]

(Last)        (First)        (Middle)

6300 NORTHAM DRIVE, 

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director                            ___ X ___ 10% Owner
_____ Officer (give title below)          _____ Other (specify below)

(Street)

MISSISSAUGA, ONTARIO, A6 L4V 1H7       

(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   6307484   D   (1)  

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)  Mosaic Venture Partners II, Limited Partnership ("Mosaic") is the record owners of these shares. 1369904 Ontario, Inc. ("Ontario"), as the general partner of Mosaic, has voting and investment control of the shares held by Mosaic. David Samuel and Vernon Lobo are Managing Directors of Ontario and may be deemed to share voting and investment power with respect to the shares held by Mosaic. Mr. Samuel and Mr. Lobo disclaim beneficial ownership of all shares held by Mosaic except to the extent of their pecuniary interest therein.

Remarks:
Exhibit List
Exhibit 24 - Limited Power of Attorney

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
Mosaic Venture Partners II Limited Partnership
6300 NORTHAM DRIVE
MISSISSAUGA, ONTARIO, A6 L4V 1H7
X

Samuel David G.
C/O BIRCH HILL EQUITY PARTNERS 100
WELLINGTON ST, W. SUITE 2300, PO BOX 22
TORONTO, ONTARIO, A6 M5K 1A1
X

1369904 Ontario, Inc.
C/O MOSAIC VENTURE PARTNERS II, L.P.
6300 NORTHAM DRIVE
MISSISSAUGA, ONTARIO, A6 L4V 1H7
X

Lobo Vernon F
C/O MOSAIC VENTURE PARTNERS II, L.P.
6300 NORTHAM DRIVE
MISSISSAUGA, ONTARIO, A6 L4V 1H7
X


Signatures
/s/ Vernon Lobo, authorized signatory of 1369904 Ontario Inc., the general partner of the Reporting Person 4/3/2014
** Signature of Reporting Person Date

/s/ Frances Dea, attorney-in-fact 4/3/2014
** Signature of Reporting Person Date

/s/ Vernon Lobo, authorized signatory of the Reporting Owner 4/3/2014
** Signature of Reporting Person Date

/s/ Vernon Lobo 4/3/2014
** Signature of Reporting Person Date


Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.