13G Filing: Sabby Capital Opens Large Position in Rexahn Pharmaceuticals, Inc. (RNN)

Item 1.
(a).
Name of Issuer:

Rexahn Pharmaceuticals, Inc.

(b).
Address of issuer’s principal executive offices:

15245 Shady Grove Road, Suite 455, Rockville, MD 20850

Item 2.
(a).
Name of person filing:

Sabby Healthcare 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 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 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.:

761640 10 1

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: