X0306 4 2021-02-17 1 0001660280 Tenable Holdings, Inc. TENB 0001305473 Insight Holdings Group, LLC C/O INSIGHT PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001745335 Insight Venture Associates IX, Ltd. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001745334 Insight Venture Associates IX, L.P. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001629398 Insight Venture Partners IX, L.P. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001629399 Insight Venture Partners (Cayman) IX, L.P. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001629396 Insight Venture Partners (Delaware) IX, L.P. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 0001629402 Insight Venture Partners IX (Co-Investors), L.P. C/O INSIGHT VENTURE PARTNERS 1114 AVENUE OF THE AMERICAS, 36TH FLOOR NEW YORK NY 10036 0 0 1 0 Common Stock 2021-02-17 4 J 0 924289 D 3111873 I See footnote Common Stock 2021-02-17 4 J 0 459257 D 1546213 I See footnote Common Stock 2021-02-17 4 J 0 97928 D 329702 I See footnote Common Stock 2021-02-17 4 J 0 18450 D 62114 I See footnote See Exhibit 99.1 See Exhibit 99.1 See Exhibit 99.1 See Exhibit 99.1 See Exhibit 99.1 This Form 4 is the first of two Forms 4 filed relating to the same event. The 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, Insight Holdings Group, LLC. Exhibit List ------------ Exhibit 99.1 - Explanation of Responses Exhibit 99.2 - Joint Filers' Signatures Exhibit 99.3 - Joint Filer Information Insight Holdings Group, LLC, its Authorized Signatory, /s/ Andrew Prodromos 2021-02-19