Underwriting Agreement

On December 14, 2016, Diamondback Energy, Inc. (Diamondback)
entered into an Underwriting Agreement (the Underwriting
Agreement) with Credit Suisse Securities (USA) LLC, acting on
behalf of itself and as the representative of the several
underwriters (the Underwriters). The Underwriting Agreement
relates to a public offering by Diamondback of 10,500,000 shares
of its common stock (the Firm Share Offering) at a purchase price
to the Underwriters of $95.3025 per share (the Purchase Price).
to the Underwriting Agreement, Diamondback granted the
Underwriters a 30-day option (the Option) to purchase up to
1,575,000 additional shares of its common stock at the Purchase
Price (together with the Firm Share Offering, the Common Stock
Offering), which option was exercised in full by the Underwriters
on December 15, 2016. The Underwriters will offer the shares
acquired in the Common Stock Offering from time to time for sale
in one or more transactions on the NASDAQ Global Select Market,
in the over-the-counter market, through negotiated transactions
or otherwise at market prices prevailing at the time of sale, at
prices related to prevailing market prices or at negotiated
prices. Diamondback intends to use the estimated net proceeds
from the Common Stock Offering of approximately $1,150.5 million
(after deducting underwriting discounts and commissions and
estimated offering expenses), together with the net proceeds from
the Notes Offering (defined below under the heading Notes
Purchase Agreement) and cash on hand, to fund the cash
consideration for Diamondbacks previously announced pending
acquisition (the Pending Acquisition) of certain oil and natural
gas assets of Brigham Resources Operating, LLC and Brigham
Resources Midstream, LLC (collectively, the Sellers). In
addition, Diamondback intends to use any net proceeds that may
become available if the Pending Acquisition is not consummated or
the purchase price is reduced because it acquires less than all
of the oil and natural gas assets subject to the purchase and
sale agreement with the Sellers, to fund a portion of
Diamondbacks exploration and development activities and for
general corporate purposes, which may include leasehold interest
and property acquisitions and working capital. The Common Stock
Offering closed on December 20, 2016.

The Underwriting Agreement contains customary representations,
warranties and agreements of Diamondback and other customary
obligations of the parties and termination provisions. The
Underwriting Agreement also provides for the indemnification by
Diamondback of the Underwriters against certain liabilities,
including liabilities under the Securities Act of 1933, as
amended (the Securities Act).

The Common Stock Offering was made to Diamondbacks effective
automatic shelf registration statement on Form S-3 (File No.
333-214892), filed with the Securities and Exchange Commission
(the SEC) on December 2, 2016 (the Shelf Registration Statement),
and a prospectus, which consists of a base prospectus, filed with
the SEC on December 2, 2016, a preliminary prospectus supplement,
filed with the SEC on December 14, 2016, and a final prospectus
supplement, filed with the SEC on December 16, 2016
(collectively, the Prospectus).

Certain of the Underwriters and their affiliates have from time
to time performed, and may in the future perform, various
financial advisory, commercial banking and investment banking
services for Diamondback and its affiliates in the ordinary
course of business for which they have received and would receive
customary compensation.

The preceding summary of the Underwriting Agreement is qualified
in its entirety by reference to the full text of such agreement,
a copy of which is attached as Exhibit 1.1 to this Current Report
on Form 8-K and incorporated herein by reference.

Notes Purchase Agreement

On December 15, 2016, Diamondback and certain subsidiary
guarantors entered into a Notes Purchase Agreement (the Notes
Purchase Agreement) with Credit Suisse Securities (USA) LLC, as
representative of the several initial purchasers named therein
(the Initial Purchasers), in connection with Diamondbacks private
placement of senior notes. The Notes Purchase Agreement provides
for, among other things, the issuance and sale by Diamondback of
$500 million in aggregate principal amount of 5.375% Senior Notes
due 2025 (the Notes) to qualified institutional buyers to Rule
144A under the Securities Act, and to certain non-U.S. persons in
accordance with Regulation S under the Securities Act (the Notes
Offering). Diamondback and the subsidiary guarantors of the Notes
have agreed to indemnify the Initial Purchasers against certain
liabilities, including liabilities under the Securities Act, or
to contribute to payments the Initial Purchasers may be required
to make because of any of such liabilities. Under the Notes
Purchase Agreement, Diamondback also agreed to a 90-day lock-up
with respect to, among other things, an offer, sale or other
disposition of its debt securities, subject to certain
exceptions.

Diamondback intends to use the net proceeds from the Notes
Offering, together with the net proceeds from the Common Stock
Offering and cash on hand, to fund the cash consideration for the
Pending Acquisition. The Notes Offering closed on December 20,
2016.

Certain of the Initial Purchasers and their affiliates have, from
time to time, performed, and may in the future perform, various
financial advisory, commercial banking and investment banking
services for Diamondback and its affiliates in the ordinary
course of business for which they have received and would receive
customary compensation.

The preceding summary of the Notes Purchase Agreement is
qualified in its entirety by reference to the full text of such
agreement, a copy of which is attached as Exhibit 10.1 to this
Current Report on Form 8-K and incorporated herein by reference.

Credit Agreement Amendment

On December 15, 2016, Diamondback, as parent guarantor,
Diamondback OG LLC, as borrower, and certain other subsidiaries
of Diamondback, as guarantors, entered into a fourth amendment
(the Fourth Amendment) to the Second Amended and Restated Credit
Agreement, dated as of November 1, 2013, with Wells Fargo Bank,
National Association, as administrative agent, and the lenders
party thereto (as amended, the Credit Agreement). The Fourth
Amendment increases the amount of unsecured senior notes that
Diamondback is permitted to issue from $750 million to $1.0
billion.

The preceding summary of the Fourth Amendment is qualified in its
entirety by reference to the full text of such amendment, a copy
of which is attached as Exhibit 10.2 to this Current Report on
Form 8-K and incorporated herein by reference.

Item 8.01. Other Events.

Legal Opinion

In connection with the Common Stock Offering, Diamondback is
filing a legal opinion of Akin Gump Strauss Hauer Feld LLP,
attached as Exhibit 5.1 to this Current Report on Form 8-K, to
incorporate such opinion by reference into the Shelf Registration
Statement and into the Prospectus.

Item 9.01. Financial Statements and Exhibits.