UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. )*
ARCA Biopharma, Inc.
(Name of Issuer)
Common Stock
(Title of Class of Securities)
00211Y100
(CUSIP Number)
May 30, 2013
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which
this Schedule is filed:
[_] Rule 13d-1(b)
[X] Rule 13d-1(c)
[_] Rule 13d-1(d)
__________
*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).
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CUSIP No.
00211Y100
1.
NAME OF REPORTING PERSONS
Sabby Healthcare Volatility Master Fund, Ltd.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
(a) [_]
(b) [X]
3.
SEC USE ONLY
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5.
SOLE VOTING POWER
0
6.
SHARED VOTING POWER
318,238
7.
SOLE DISPOSITIVE POWER
0
8.
SHARED DISPOSITIVE POWER
318,238
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
318,238
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES (SEE INSTRUCTIONS)
[_]
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
9.99
12.
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
CO?
CUSIP No.
00211Y100
1.
NAME OF REPORTING PERSONS
Sabby Volatility Warrant Master Fund, Ltd.
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
(a) [_]
(b) [X]
3.
SEC USE ONLY
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5.
SOLE VOTING POWER
0
6.
SHARED VOTING POWER
318,238
7.
SOLE DISPOSITIVE POWER
0
8.
SHARED DISPOSITIVE POWER
318,238
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
318,238
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES (SEE INSTRUCTIONS)
[_]
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
9.99
12.
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
CO?
CUSIP No.
00211Y100
1.
NAME OF REPORTING PERSONS
Sabby Management, LLC
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
(a) [_]
(b) [X]
3.
SEC USE ONLY
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware, USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5.
SOLE VOTING POWER
0
6.
SHARED VOTING POWER
318,238
7.
SOLE DISPOSITIVE POWER
0
8.
SHARED DISPOSITIVE POWER
318,238
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
318,238
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES (SEE INSTRUCTIONS)
[_]
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
9.99
12.
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
OO
CUSIP No.
00211Y100
1.
NAME OF REPORTING PERSONS
Hal Mintz
2.
CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)
(a) [_]
(b) [X]
3.
SEC USE ONLY
4.
CITIZENSHIP OR PLACE OF ORGANIZATION
USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH
5.
SOLE VOTING POWER
0
6.
SHARED VOTING POWER
318,238
7.
SOLE DISPOSITIVE POWER
0
8.
SHARED DISPOSITIVE POWER
318,238
9.
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
318,238
10.
CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES (SEE INSTRUCTIONS)
[_]
11.
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
9.99
12.
TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
IN?
CUSIP No.
00211Y100
Item 1.
(a).
Name of Issuer:
ARCA Biopharma, Inc.
(b).
Address of issuer's principal executive offices:
8001 Arista Place, Suite 200, Broomfield, CO 80021
Item 2.
(a).
Name of person filing:
Sabby Healthcare Volatility Master Fund, Ltd.
Sabby Volatility Warrant Master Fund, Ltd.
Sabby Management, LLC
Hal Mintz
(b).
Address or principal business office or, if none, residence:
Sabby Healthcare Volatility Master Fund, Ltd.
c/o Ogier Fiduciary Services (Cayman) Limited
89 Nexus Way, Camana Bay
Grand Cayman KY1-9007
Cayman Islands
Sabby Volatility Warrant Master Fund, Ltd.
c/o Ogier Fiduciary Services (Cayman) Limited
89 Nexus Way, Camana Bay
Grand Cayman KY1-9007
Cayman Islands
Sabby Management, LLC
10 Mountainview Road, Suite 205
Upper Saddle River, New Jersey 07458
Hal Mintz
c/o Sabby Management, LLC
10 Mountainview Road, Suite 205
Upper Saddle River, New Jersey 07458
(c).
Citizenship:
Sabby Healthcare Volatility Master Fund, Ltd. - Cayman Islands
Sabby Volatility Warrant Master Fund, Ltd. - Cayman Islands
Sabby Management, LLC - Delaware, USA
Hal Mintz - USA
(d).
Title of class of securities:
Common stock (the Common Stock), par value $0.001
(e).
CUSIP No.:
00211Y100
Item 3.
If This Statement is filed pursuant to Section 240.13d-1(b) or
240.13d-2(b), or (c), check whether the person filing is a
(a)
[_]
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).
(b)
[_]
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
(c)
[_]
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
(d)
[_]
Investment company registered under section 8 of the Investment Company
Act of 1940 (15 U.S.C. 80a-8).
(e)
[_]
An investment adviser in accordance with Section 240.13d-1(b)(1)(ii)(E);
(f)
[_]
An employee benefit plan or endowment fund in accordance with Section
240.13d-1(b)(1)(ii)(F);
(g)
[_]
A parent holding company or control person in accordance with Section
240.13d-1(b)(1)(ii)(G);
(h)
[_]
A savings association as defined in Section 3(b) of the Federal Deposit
Insurance Act (12 U.S.C.1813);
(i)
[_]
A church plan that is excluded from the definition of an investment
company under section 3(c)(14) of the Investment Company Act of 1940
(15 U.S.C. 80a-3);
(j)
[_]
A non-U.S. institution in accordance with Section 240.13d-1(b)(1)(ii)(J);
(k)
[_]
Group, in accordance with Section 240.13d-1(b)(1)(ii)(K). If filing as a
non-U.S. institution in accordance with Section 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
Item 4.
Ownership.
Provide the following information regarding the aggregate number and
percentage of the class of securities of the issuer identified in Item 1.
(a)
Amount beneficially owned:
Sabby Healthcare Volatility Master Fund, Ltd. - 318,238
Sabby Volatility Warrant Master Fund, Ltd. - 318,238
Sabby Management, LLC - 318,238
Hal Mintz - 318,238
(b)
Percent of class:
Sabby Healthcare Volatility Master Fund, Ltd. - 9.99%
Sabby Volatility Warrant Master Fund, Ltd. - 9.99%
Sabby Management, LLC - 9.99%
Hal Mintz - 9.99%
( (c)
Number of shares as to which the person has:
Sabby Healthcare Volatility Master Fund, Ltd.
( (i)
Sole power to vote or to direct the vote
0
,
( (ii)
Shared power to vote or to direct the vote
318,238
,
( (iii)
Sole power to dispose or to direct the disposition of
0
,
( (iv)
Shared power to dispose or to direct the disposition of
318,238
..
Sabby Volatility Warrant Master Fund, Ltd.
( (i)
Sole power to vote or to direct the vote
0
,
( (ii)
Shared power to vote or to direct the vote
318,238
,
( (iii)
Sole power to dispose or to direct the disposition of
0
,
( (iv)
Shared power to dispose or to direct the disposition of
318,238
..
Sabby Management, LLC
(i)
Sole power to vote or to direct the vote
0
,
( (ii)
Shared power to vote or to direct the vote
318,238
,
( (iii)
Sole power to dispose or to direct the disposition of
0
,
( (iv)
Shared power to dispose or to direct the disposition of
318,238
..
Hal Mintz
( (i)
Sole power to vote or to direct the vote
0
,
( (ii)
Shared power to vote or to direct the vote
318,238
,
( (iii)
Sole power to dispose or to direct the disposition of
0
,
( (iv)
Shared power to dispose or to direct the disposition of
318,238
..
As calculated in accordance with Rule 13d-3 of the Securities Exchange
Act of 1934, as amended, (i) Sabby Healthcare Volatility Master Fund,
Ltd. and Sabby Volatility Master Fund, Ltd. each beneficially own 318,238
shares of the Issuer's common stock (Common Stock),representing approximately
9.99% of the Common Stock, and (ii) Sabby Management, LLC and Hal Mintz each
beneficially own 318,238 shares of the Common Stock, representing
approximately 9.99% of the Common Stock. Sabby Management, LLC and Hal
Mintz do not directly own any shares of Common Stock, but each indirectly
owns 318,238 shares of Common Stock. Sabby Management, LLC, a Delaware
limited liability company, indirectly owns 318,238 shares of Common
Stock because it serves as the investment manager of Sabby Healthcare
Volatility Master Fund, Ltd. and Sabby Volatility Warrant Master Fund,
Ltd., Cayman Islands companies. Mr. Mintz indirectly owns 318,238
shares of Common Stock in his capacity as manager of Sabby Management,
LLC.
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 [ ].
?
Item 6.
Ownership of More Than Five Percent on Behalf of Another Person.
Not applicable
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
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Item 10.
Certification.
By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above 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.
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SIGNATURE
After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement is
true, complete and correct.
June 3, 2013
(Date)
Sabby Healthcare Volatility Master Fund, Ltd.
By: /s/ Joseph McIvor
Name: Joseph McIvor
Title: Authorized Person of TDF Management Ltd.,
a Director
Sabby Volatility Warrant Master Fund, Ltd.
By: /s/ Joseph McIvor
Name: Joseph McIvor
Title: Authorized Person of TDF Management Ltd.,
a Director
Sabby Management, LLC*
By: /s/ Robert Grundstein
Name: Robert Grundstein
Title: Chief Operating Officer
/s/ Hal Mintz*
Hal Mintz
*This Reporting Person disclaims beneficial ownership over the securities
reported herein except to the extent of its pecuniary interest therein.
The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is
signed on behalf of a person by his authorized representative other than
an executive officer or general partner of the filing person, evidence of
the representative's authority to sign on behalf of such person shall be
filed with the statement, provided, however, that a power of attorney for
this purpose which is already on file with the Commission may be
incorporated by reference. The name and any title of each person who
signs the statement shall be typed or printed beneath his signature.
Note. Schedules filed in paper format shall include a signed original
and five copies of the schedule, including all exhibits. See s.240.13d-7
for other parties for whom copies are to be sent.
Attention. Intentional misstatements or omissions of fact constitute
Federal criminal violations (see 18 U.S.C. 1001).
EXHIBIT 1
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JOINT FILING AGREEMENT
The undersigned hereby agree that this Statement on Schedule 13G
with respect to the beneficial ownership of shares of Common Stock of
ARCA Biopharma, Inc. is filed jointly, on behalf of each of them.
Dated: June 3, 2013
Sabby Healthcare Volatility Master Fund, Ltd.
By: /s/ Joseph McIvor
Name: Joseph McIvor
Title: Authorized Person of TDF Management Ltd.,
a Director
Sabby Volatility Warrant Master Fund, Ltd.
By: /s/ Joseph McIvor
Name: Joseph McIvor
Title: Authorized Person of TDF Management Ltd.,
a Director
Sabby Management, LLC
By: /s/ Robert Grundstein
Name: Robert Grundstein
Title: Chief Operating Officer
/s/ Hal Mintz
Hal Mintz