Sec Form 4 Filing - Accel Growth Fund II L.P. @ Tenable Holdings, Inc. - 2019-02-08

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Accel Growth Fund II L.P. 2. Issuer Name and Ticker or Trading Symbol Tenable Holdings, Inc. [ TENB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 500 UNIVERSITY AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 02/08/2019 (Street) PALO ALTO, CA94301 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/08/2019 J( 1 ) 2,094,854 D $ 0 11,870,842 D ( 2 ) Common Stock 02/08/2019 J( 1 ) 151,677 D $ 0 859,503 I By Accel Growth Fund II Strategic Partners L.P. ( 3 ) Common Stock 02/08/2019 J( 1 ) 203,872 D $ 0 1,155,272 I By Accel Growth Fund Investors 2012 L.L.C. ( 4 ) Common Stock 7,799,122 I By Accel Growth Fund III L.P. ( 5 ) Common Stock 368,202 I By Accel Growth Fund III Strategic Partners L.P. ( 6 ) Common Stock 516,699 I By Accel Growth Fund Investors 2014 L.L.C. ( 7 ) Common Stock 2,182,696 I By Accel XI L.P. ( 8 ) Common Stock 163,992 I By Accel XI Strategic Partners L.P. ( 9 ) Common Stock 231,806 I By Accel Investors 2013 L.L.C. ( 10 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Accel Growth Fund II L.P. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund II Strategic Partners L.P. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund III Associates L.L.C. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund III L.P. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund III Strategic Partners L.P. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund II Associates L.L.C. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund Investors 2012 L.L.C. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Growth Fund Investors 2014 L.L.C. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Accel Investors 2013 L.L.C. 500 UNIVERSITY AVENUE PALO ALTO, CA94301 X Signatures /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund II L.P. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund II Strategic Partners L.P. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III Associates L.L.C. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III L.P. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund III Strategic Partners L.P. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund II Associates L.L.C. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund Investors 2012 L.L.C. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Growth Fund Investors 2014 L.L.C. 02/12/2019 Signature of Reporting Person Date /s/ Tracy L. Sedlock, as Attorney-in-Fact, for Accel Investors 2013 L.L.C. 02/12/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Transactions reported on this form represent pro rata distributions, and not a purchase or sale of securities, by Accel Growth Fund II L.P., Accel Growth Fund II Strategic Partners L.P., Accel Growth Fund Investors 2012 L.L.C. to their respective general and limited partners or members without consideration. Distribution transactions were executed pursuant to a plan established in compliance with the requirements of Rule 10b5-1. ( 2 )Accel Growth Fund II Associates L.L.C. is the general partner of Accel Growth Fund II L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund II Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 3 )Accel Growth Fund II Associates L.L.C. is the general partner of Accel Growth Fund II Strategic Partners L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund II Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 4 )Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund Investors 2012 L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 5 )Accel Growth Fund III Associates L.L.C. is the general partner of Accel Growth Fund III L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund III Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 6 )Accel Growth Fund III Associates L.L.C. is the general partner of Accel Growth Fund III Strategic Partners L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund III Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 7 )Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock, Ryan J. Sweeney and Richard P. Wong are the Managing Members of Accel Growth Fund Investors 2014 L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 8 )Accel XI Associates L.L.C. is the General Partner of Accel XI L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock and Richard P. Wong are the Managing Members of Accel XI Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 9 )Accel XI Associates L.L.C. is the General Partner of Accel XI Strategic Partners L.P. and has the sole voting and investment power. Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock and Richard P. Wong are the Managing Members of Accel XI Associates L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein. ( 10 )Andrew G. Braccia, Sameer K. Gandhi, Ping Li (who is a director of the Issuer), Tracy L. Sedlock and Richard P. Wong are the Managing Members of Accel Investors 2013 L.L.C. and share voting and investment powers over such shares. The Managing Members disclaim beneficial ownership except to the extent of their pecuniary interest therein.

Remarks: This Form 4 is the first of two Form 4s filed relating to the same event. Combined, the two reports report the holdings for the following reporting persons: Accel Growth Fund II L.P., Accel Growth Fund II Strategic Partners L.P., Accel Growth Fund II Associates L.L.C., Accel Growth Fund III L.P., Accel Growth Fund III Strategic Partners L.P., Accel Growth Fund III Associates L.L.C., Accel XI L.P., Accel XI Strategic Partners L.P., Accel XI Associates L.L.C., Accel Growth Fund Investors 2012 L.L.C., Accel Investors 2013 L.L.C. and Accel Growth Fund Investors 2014 L.L.C. This Form 4 has been split into two filings because there are more than 10 reporting persons in total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10 reporting persons. Each Form 4 is filed by designated filer Accel Growth Fund II L.P.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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