144 0001846877 XXXXXXXX LIVE 0001288847 Five9, Inc. 001-36383 3001 BISHOP DR., STE. #350 San Ramon CA 94583 925-201-2000 Leena Mansharamani Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004 2573 64404.92 74723569 06/04/2026 Nasdaq Common 06/03/2026 RSU Issuer N 2573 06/03/2026 Not Applicable N Leena Mansharamani 3001 Bishop Drive Suite 350 San Ramon CA 94583 Common 03/04/2026 1926 34417.62 The sale reported on this Form 144 represents an Issuermandated sale by the Reporting Person to cover taxwithholding obligations in connection with the vesting andsettlement of Restricted Stock Units, and it does notrepresent a discretionary trade by the Reporting Person. 06/03/2026 Leena Mansharamani