13D Filing: Elliott Associates, L.P. and Imperva Inc (IMPV)

If the filing person has previously filed a statement on Schedule
13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), Rule
13d-1(f) or Rule 13d-1(g), check the following box. [ ]

(Page 1 of 7 Pages)

______________________________

* 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 disclosures provided in a prior cover page.

The information required on 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).

The following constitutes Amendment No. 3 to the Schedule 13D filed
by the undersigned (the “Amendment No. 3”). This Amendment No. 3 amends the Schedule 13D as specifically set forth herein.

The Reporting Persons
may effect purchases of shares of Common Stock through margin accounts maintained for them with prime brokers, which extend margin
credit as and when required to open or carry positions in their margin accounts, subject to applicable federal margin regulations,
stock exchange rules and such firms’ credit policies. Positions in shares of Common Stock may be held in margin accounts and may
be pledged as collateral security for the repayment of debit balances in such accounts. Since other securities may be held in such
margin accounts, it may not be possible to determine the amounts, if any, of margin used to purchase shares of Common Stock.

Item 5(a) is hereby amended and restated to read as follows:

(a)       As
of the date hereof, Elliott, Elliott International and EICA collectively have combined economic exposure in the Issuer of approximately
8.4% of the shares of Common Stock outstanding.

The aggregate percentage
of Common Stock reported owned by each person named herein is based upon 34,013,911 shares of Common Stock outstanding as of October
31, 2017, which is the total number of shares of Common Stock outstanding as reported in the Issuer’s Quarterly Report on Form
10-Q for the quarterly period ended September 30, 2017 filed with the Securities and Exchange Commission on November 9, 2017.

As of the date hereof,
Elliott beneficially owned 650,036 shares of Common Stock, constituting approximately 1.9% of the shares of Common Stock outstanding..

As of the date hereof,
Elliott International beneficially owned 1,381,327 shares of Common Stock, constituting approximately 4.1% of the shares of Common
Stock outstanding. EICA, as the investment manager of Elliott International, may be deemed to beneficially own the 1,381,327 shares
of Common Stock beneficially owned by Elliott International, constituting approximately 4.1% of the shares of Common Stock outstanding.

Collectively, Elliott,
Elliott International and EICA beneficially own 2,031,363 shares of Common Stock, constituting approximately 6.0% of the shares
of Common Stock outstanding.

Collectively, Elliott,
Elliott International and EICA have economic exposure comparable to approximately 2.5% of the shares of Common Stock outstanding
pursuant to the Derivative Agreements, as disclosed in Item 6.

Item 5(c) is hereby amended and restated to read as follows:

(c)       The
transactions effected by the Reporting Persons during the past 60 days are set forth on Schedule 1 attached hereto.

The first three paragraphs of Item 6 are hereby amended and
restated to read as follows:

Elliott,
through The Liverpool Limited Partnership, a Bermuda limited partnership and a wholly-owned subsidiary of Elliott (“Liverpool”),
and Elliott International have entered into notional principal amount derivative agreements (the “Derivative Agreements”)
in the form of cash settled swaps with respect to 268,828 and 571,258 shares of Common Stock of the Issuer, respectively (representing
economic exposure comparable to approximately less than 1% and 1.7% of the shares of Common Stock of the Issuer, respectively).
Collectively, the Derivative Agreements held by the Reporting Persons represent economic exposure comparable to an interest in
approximately 2.5% of the shares of Common Stock. The Derivative Agreements provide Elliott and Elliott International with economic
results that are comparable to the economic results of ownership but do not provide them with the power to vote or direct the voting
or dispose of or direct the disposition of the shares that are referenced in the Derivative Agreements (such shares, the “Subject
Shares”). The Reporting Persons disclaim beneficial ownership in the Subject Shares. The counterparties to the Derivative
Agreements are unaffiliated third party financial institutions.

Elliott sold to counterparties call options that provided the counterparty the right to buy from Elliott up to 32,000 shares of Common
Stock at a price of $42.50 per share, if such right was exercised prior to or on January 19, 2018. Such call options were exercised
on January 19, 2018.

Elliott
International sold to counterparties call options that provided the counterparty the right to buy from Elliott International
up to 68,000 shares of Common Stock at a price of $42.50 per share, if such right was exercised prior to or on January 19,
2018. Such call options were exercised on January 19, 2018.

SIGNATURES

After reasonable
inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in
this statement is true, complete and correct.

DATE: January 23, 2018

SCHEDULE 1

Transactions of the Reporting Persons Effected
During the Past 60 Days

The following table sets forth all the transactions in the Common
Stock effected by Elliott Associates, L.P. during the past 60 days.

* Exercise of options reported in this Amendment No. 3.

The following table sets forth all the transactions in the Common
Stock effected by Elliott International, L.P. during the past 60 days.

* Exercise of options reported in this Amendment No. 3.