to Bats stockholders, in the aggregate. No fractional shares of
CBOE Holdings Common Stock were issued in the Merger.
Accordingly, Bats stockholders became entitled to receive cash
in lieu of fractional shares, if any, of CBOE Holdings Common
Stock.

to the Merger Agreement, at the Effective Time, each
outstanding unexercised option to purchase Bats Common Stock
granted under any Bats equity incentive plan, whether vested or
unvested (Bats Stock
Options), was converted into an option to
purchase shares of CBOE Holdings Common Stock
(CBOE
Holdings Stock Options), with the same terms and
conditions (including vesting schedule) as were applicable to
such Bats Stock Option (but taking into account any changes,
including any acceleration of vesting of such Bats Stock
Option, occurring by reason of the transactions contemplated by
the Merger Agreement). The number of shares of CBOE Holdings
Common Stock subject to each such CBOE Holdings Stock Option is
equal to the number of shares of Bats Common Stock subject to
the corresponding Bats Stock Option immediately prior to the
Effective Time multiplied by 0.4452, and the exercise price of
such CBOE Holdings Stock Option is equal to the per share
exercise price under the corresponding Bats Stock Option
divided by 0.4452 (subject to rounding).

to the Merger Agreement, at the Effective Time, each
outstanding unvested award of restricted Bats Common Stock
granted under any Bats equity incentive plan
(Bats
Restricted Shares) was assumed by CBOE Holdings
and was converted into an award of restricted shares of CBOE
Holdings Common Stock (CBOE Holdings Restricted
Shares), subject to the same terms and conditions
(including vesting schedule) that applied to the applicable
Bats Restricted Shares immediately prior to the Effective Time
(but taking into account any changes, including any
acceleration of vesting of such Bats Restricted Shares,
occurring by reason provided for in the Merger Agreement). The
number of shares of CBOE Holdings Common Stock subject to each
such award of CBOE Holdings Restricted Shares is equal to the
number of shares of Bats Common Stock subject to the
corresponding Bats Restricted Share award multiplied by 0.4452
(subject to rounding).

The foregoing description of the Merger, the Subsequent Merger
and the Merger Agreement is not complete and is qualified in
its entirety by reference to the Merger Agreement, which CBOE
Holdings filed with the SEC as Exhibit2.1 to the Current Report
on Form8-K on September28, 2016 and is incorporated herein by
reference.

The Merger Agreement has been referenced in this Current Report
on Form8-K to provide investors and stockholders with
information regarding its terms. It is not intended to provide
any other factual information about CBOE Holdings, Bats, Merger
Sub or Merger LLC. The representations, warranties and
covenants contained in the Merger Agreement were made only for
purposes of that agreement and as of specific dates, were
solely for the benefit of the parties to the Merger Agreement,
may be subject to limitations agreed upon by the contracting
parties, including being qualified by confidential disclosures
made for the purposes of allocating contractual risk between
the parties to the Merger Agreement instead of establishing
these matters as facts, and may be subject to standards of
materiality applicable to the contracting parties that differ
from those applicable to investors. Investors are not
third-party beneficiaries under the Merger Agreement and should
not rely on the representations, warranties and covenants or
any descriptions thereof as characterizations of the actual
state of facts or condition of CBOE Holdings, Bats, Merger Sub
or Merger LLC or any of their respective subsidiaries or

affiliates. Moreover, information concerning the subject matter
of the representations and warranties may have changed after
the date of the Merger Agreement, which subsequent information
may or may not be fully reflected in CBOE Holdings or Bats
public disclosures.

The information set forth under Item 2.03 below is incorporated
herein by reference. Merrill Lynch, Pierce, Fenner Smith
Incorporated (MLPFS) and Bank
of America, N.A. are parties to a commitment letter providing
for a potential bridge loan facility to CBOE Holdings in
connection with the Merger as previously disclosed in CBOE
Holdings Current Report on Form8-K filed with the SEC on
September28, 2016. Also, MLPFS, Morgan Stanley MUFG Loan
Partners, LLC, Citibank, N.A., JPMorgan Chase Bank, N.A.,
certain Term Lenders (as defined below) or certain of their
respective affiliates (collectively, the Permit Holders)
are trading permit holders and engage in trading activities on
CBOE Holdings exchanges. In addition, certain of the Permit
Holders are clearing members of the Options Clearing
Corporation, and, as such, these Permit Holders clear the
market-maker sides of transactions at CBOE Holdings exchanges.

Item 2.03. Creation of Direct Financial Obligation or
an Obligation under an Off-Balance Sheet Arrangement of a
Registrant.

As previously disclosed, on December15, 2016, CBOE Holdings
entered into a Term Loan Credit Agreement (the
Term Loan
Agreement) with Bank of America, N.A., as
administrative agent, certain lenders named therein (the
Term Loan
Lenders), MLPFS, as sole lead arranger and sole
bookrunner, Morgan Stanley MUFG Loan Partners, LLC, as
syndication agent, and Citibank, N.A., PNC Bank, National
Association and JPMorgan Chase Bank, N.A., as co-documentation
agents, to which, subject to the conditions set forth in the
Term Loan Agreement, the Term Loan Lenders committed to provide
a senior unsecured delayed draw term loan facility in an
aggregate principal amount of $1.0 billion.

On February28, 2017, CBOE Holdings made a draw under the Term
Loan Agreement in the aggregate amount of $1,000,000,000. CBOE
Holdings used the proceeds to finance a portion of the cash
component of the aggregate consideration for the Merger, repay
certain existing indebtedness of Bats, pay fees and expenses
incurred in connection with the transactions contemplated by
the Merger Agreement and fund working capital needs and for
other general corporate purposes.

The description of the Term Loan Agreement in Item 1.01 of CBOE
Holdings Current Report on Form8-K filed with the SEC on
December20, 2016 is hereby incorporated herein by reference.

Item 5.02. Departure of Directors or Certain Officers;
Election of Directors; Appointment of Certain Officers;
Compensatory Arrangements of Certain Officers.

Board Composition

The Merger Agreement provides that CBOE Holdings will take all
requisite actions so that, as of the Effective Time, the CBOE
Holdings board of directors (the Board) will
consist of 14 directors, including three individuals designated
by Bats who were serving on the Bats

board of directors immediately prior to the Effective Time and
comply with the policies of the Nominating and Governance
Committee of the Board disclosed to Bats. As previously
disclosed, each of Chris Mitchell, Joe Ratterman and Michael
Richter was elected to the Board effective as of the Effective
Time, and each of William J. Brodsky, R. Eden Martin and Susan
M. Phillips (collectively, the Resigning
Directors) resigned from the Board, effective as
of the Effective Time. As previously disclosed, any unvested
restricted stock awards held by any Resigning Director vested
at the Effective Time. In addition, each Resigning Director was
entitled to receive at the Effective Time any retainer payments
that would have been payable to such Resigning Director if such
Resigning Director had not ceased to serve on the Board prior
to CBOE Holdings 2017 annual meeting of stockholders.

Amended and Restated Employment Agreement with Chief
Executive Officer

In connection with the Merger and in order to reflect certain
changes, CBOE Holdings, Chicago Board Options
Exchange,Incorporated and C2 Options Exchange,Incorporated
(collectively, the Company)
entered into an amended and restated employment agreement,
dated as of February27, 2017, with Edward T. Tilly, the Chief
Executive Officer of the Company. The material changes from
Mr.Tillys prior employment agreement, which was entered into
effective January1, 2013, are as follows:

(i) in addition to reflecting the title and duties of Mr.Tilly
as Chief Executive Officer, the amended and restated employment
agreement also reflects Mr.Tillys appointment as Chairman of
the Board effective upon the consummation of the Merger;

(ii) the amended and restated employment agreement establishes
a new employment term lasting until December31, 2019, with
automatic subsequent one-year renewal periods in the absence of
notice from the parties;

(iii) the amended and restated employment agreement provides
for an annual base salary of $1,150,000, a 2017 target annual
bonus of $1,897,500 payable in cash, and a 2017 target annual
equity incentive compensation award with a grant date value of
$3,000,000;

(iv) the amended and restated employment agreement provides for
the pro-rated bonus payable upon a qualifying termination of
Mr.Tillys employment to be based on actual performance for the
year in which the termination occurs; and

(v) the definition of change in control under the agreement has
been amended to match the definition under the Second Amended
and Restated CBOE Holdings,Inc. Long-Term Incentive Plan.

Appointment of President and Chief Operating Officer

As previously disclosed, on February16, 2017, the Board
appointed Chris Concannon, President and Chief Executive
Officer of Bats, to serve as President and Chief Operating
Officer of the Company, effective as of the Effective Time. The
Company has entered into an employment agreement with
Mr.Concannon, dated as of February27, 2017 (the
Employment
Agreement), to which Mr.Concannon assumed the
title of President and Chief Operating Officer of the Company
effective upon the consummation of the Merger (the

Effective
Date). The initial term of the Employment
Agreement ends on December31, 2019, but the Employment
Agreement will automatically renew thereafter for successive
one-year terms, unless either the Company or Mr.Concannon
provides written notice of non-renewal at least 180 days prior
to the expiration of the then-current term.

The Employment Agreement provides for an annual base salary of
$1,000,000 and for eligibility to participate in any bonus or
incentive program applicable to other senior executives, with
an initial target annual bonus of $1,500,000. The Employment
Agreement also provides that Mr.Concannon will be eligible to
receive equity incentive awards in the sole discretion of the
Compensation Committee of the Board, provided that the initial
target annual equity incentive award to be granted as of the
first annual grant date following the Effective Date will have
a grant date value of $2,000,000. In addition, the Employment
Agreement provides for a special one-time grant of restricted
stock units with a grant date value of $2,000,000 (the
Special RSU
Award), which will vest in full upon the third
anniversary of the Effective Date provided that Mr.Concannon
remains in continuous employment through such date (subject to
accelerated vesting as described below). The Employment
Agreement also generally provides that Mr.Concannon is entitled
to participate in all of the Companys employee benefit plans
that are generally available to senior executives, other than
the frozen Chicago Board Options Exchange,Incorporated
Executive Retirement Plan.

Under the Employment Agreement, upon a termination of
employment by the Company without cause or by Mr.Concannon for
good reason, Mr.Concannon will be entitled to receive the
following: (i)accrued but unpaid base salary through the date
of termination; (ii)a pro-rated bonus equal to the bonus that
Mr.Concannon would have received for the calendar year in which
termination occurs, based on actual performance, pro-rated for
the portion of the calendar year worked (the Pro-Rated
Bonus); (iii)a lump sum cash severance payment in
an amount equal to (1)if the termination of employment occurs
within 24 months immediately following the Effective Date, the
sum of (A)two times the annual base salary in effect on the
date of termination and (B)two times the target bonus for the
year of termination, or (2)if the termination of employment
occurs after the 24-month period immediately following the
Effective Date, the sum of (A)one times the annual base salary
in effect on the date of termination and (B)one times the
target bonus for the year of termination; (iv)a lump sum cash
payment in an amount equal to (1)if the termination of
employment occurs within 24 months immediately following the
Effective Date, the aggregate amount of all employer
contributions Mr.Concannon would have received had his
employment continued for a period of two years under the
Chicago Board Options Exchange SMART Plan and the Chicago Board
Options Exchange,Incorporated Supplemental Retirement Plan, or
(2)if the termination of employment occurs after the 24-month
period immediately following the Effective Date, the aggregate
amount of all employer contributions Mr.Concannon would have
received had his employment continued for a period of one year
under the Chicago Board Options Exchange SMART Plan and the
Chicago Board Options Exchange,Incorporated Supplemental
Retirement Plan; (v)accelerated vesting of all outstanding
equity awards granted by Bats prior to the consummation of the
Merger and assumed to the Merger Agreement (the
Bats Equity
Acceleration); (vi)accelerated vesting of any
unvested portion of the Special RSU Award; and
(vii)Company-paid premiums for coverage under the Consolidated
Omnibus Budget Reconciliation Act of 1985, as amended
(COBRA), or an
amount equal to Mr.Concannons COBRA premiums, sufficient to
cover full family health care for a period of either (A)18
months following the

termination of employment, if the termination of employment
occurs within the 24-month period immediately following the
Effective Date, or (B)12 months following the termination of
employment, if the termination of employment occurs after the
24-month period immediately following the Effective Date.

Upon a termination of employment without cause or for good
reason during the 18 months following a change in control,
Mr.Concannon will also be entitled to the severance benefits
described in clauses (i)through (vii)in the paragraph above,
provided that with respect to clauses (iii), (iv)and (vii),
Mr.Concannon will be entitled to the maximum amounts described
above. If Mr.Concannons employment is terminated due to death
or disability, Mr.Concannon (or Mr.Concannons estate, as
applicable) will be entitled to receive (i)annual base salary
through the date of termination; (ii)the Pro-Rated Bonus; and
(iii)the Bats Equity Acceleration. to the Employment Agreement,
Mr.Concannon has agreed to certain non-competition and
non-solicitation provisions during the employment term and for
two years thereafter, as well as indefinite confidentiality
obligations.

Amendment and Restatement of Executive Severance Plan

In connection with the Merger, CBOE Holdings amended and
restated the CBOE Holdings,Inc. Executive Severance Plan (the
Severance
Plan), under which eligible executives are
entitled to certain severance benefits upon a qualifying
termination of employment. The material changes to the
Severance Plan include:

(i) the inclusion of the following Bats executives as
participants in the Severance Plan beginning 24 months after
the closing of the Merger, when they cease to be eligible for
change in control severance benefits under their employment
agreements with Bats: Eric Crampton, Bryan Harkins, Mark
Hemsley, David Howson, Christopher Isaacson and Brian N.
Schell;

(ii) a change in the definition of Good Reason to reflect the
employment location of the Bats participants after the Merger;

(iii) a change in the calculation of the pro-rated bonus
payment that is payable upon a qualifying termination of
employment to be based on the level at which the Company
actually achieves applicable performance goals, rather than the
target level of performance; and

(iv) a reduction in the severance multiplier for new
participants in the Severance Plan from two times the sum of a
participants annual base salary and target annual bonus to one
times the sum of a participants annual base salary and target
annual bonus.

Retirement of Certain Executive Officers

Each of Edward L. Provost, President and Chief Operating
Officer of CBOE Holdings, and Gerald OConnell, Chief Technology
Officer of CBOE Holdings, retired from CBOE Holdings effective
as of the Effective Time. As previously disclosed, in
connection with their termination of employment, each of
Messrs.Provost and OConnell, became entitled to (i)the
severance benefits payable under the terms of the CBOE Holdings
Executive Severance Plan, (ii)

accelerated vesting in full of any outstanding restricted stock
units held by the executive, with the restricted stock unit
award for 2016 performance paid in the form of cash, and
(iii)accelerated vesting of any outstanding performance share
units, held by the executive, prorated for the portion of the
performance period completed at the time of termination and
subject to attainment of the applicable performance goals
through the full performance period. Mr.OConnell is 65 years of
age and, as such, is entitled to the accelerated vesting of his
restricted stock units and performance share units in the
manner described in clauses (ii)and (iii), above, upon
retirement. Mr.Provost is 64 years of age and otherwise would
have become entitled to the accelerated vesting of his
restricted stock units and performance share units in the
manner described in clauses (ii)and (iii), above, if he had
retired on or after attaining age 65.

Item 8.01. Other Events.

CBOE Holdings and Bats will each treat the Merger and the
Subsequent Merger, taken together, as a reorganization under
Section368(a)of the Internal Revenue Code. For a discussion of
the qualification of the Merger and the Subsequent Merger,
taken together, as a reorganization and the material U.S.
federal income tax consequences of the exchange of Bats Common
Stock for CBOE Holdings Common Stock and cash in the Merger,
see the discussion under the heading The Merger Material U.S.
Federal Income Tax Consequences in the Prospectus. Under the
Merger Agreement, it was a condition to the obligation of each
of CBOE Holdings and Bats to complete the Merger that CBOE
Holdings and Bats each receive an opinion of its counsel as to
certain tax matters specified in the Merger Agreement. CBOE
Holdings and Bats each received such opinion on the closing
date.

Item 9.01. Financial Statements and Exhibits.

(a)Financial Statements of Business Acquired.

The required financial statements for Bats called for by Item
9.01(a)were included in the Current Report on Form8-K filed by
CBOE Holdings with the SEC on January3, 2017 and are
incorporated herein by reference.

(b)Pro Forma Financial Information.

The required pro forma financial information called for by Item
9.01(b)was included in the Current Report on Form8-K filed by
CBOE Holdings with the SEC on January3, 2017 and is
incorporated herein by reference.

(d)Exhibits.

* Schedules have been omitted to Item 601(b)(2)of Regulation
S-K. A copy of any omitted schedule will be furnished
supplementally to the SEC upon request.

to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its
behalf by the undersigned hereunto duly authorized.

EXHIBITINDEX

* Schedules have been omitted