144
0001991099
XXXXXXXX
LIVE
0001835830
Klaviyo, Inc.
001-41806
125 Summer Street, 6th Floor
Boston
MA
02110
6172131788
ANDREW BIALECKI
Director
Officer
10% Stockholder
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
1350000
38016000.00
137856147
12/02/2025
NYSE
Common
05/14/2025
Previously Exercised Stock Options
Issuer
N
1350000
05/14/2025
Cash
N
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
12/01/2025
12903
365334.25
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/28/2025
12903
370294.16
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/26/2025
12903
366454.23
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/25/2025
12903
370820.61
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/24/2025
144717
4017112.37
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/24/2025
12903
358675.01
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/21/2025
12903
359344.68
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/20/2025
12903
356460.86
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/19/2025
12903
352760.28
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/18/2025
147329
4001028.39
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/18/2025
12903
348839.06
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/17/2025
12903
350098.39
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/14/2025
12903
369785.79
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/13/2025
12903
359949.83
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/12/2025
12903
376626.96
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/11/2025
140464
4177655.96
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/11/2025
12903
385391.97
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/10/2025
12903
383108.13
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/07/2025
12903
390123.50
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/06/2025
12903
356205.38
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/05/2025
12903
334465.11
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
11/04/2025
25806
654440.16
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/31/2025
12903
328764.57
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/30/2025
25806
657526.56
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/28/2025
12903
336902.49
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/27/2025
12903
339963.08
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/24/2025
12903
343484.31
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/23/2025
12903
337129.58
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/22/2025
12903
333143.85
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/21/2025
12903
335394.13
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/20/2025
12903
310304.25
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/17/2025
12903
305421.75
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/16/2025
12903
309332.65
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/15/2025
12903
314875.78
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/14/2025
163331
3981078.79
ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/14/2025
12903
315884.79
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
10/07/2025
159508
4034531.55
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
09/30/2025
137224
3960351.89
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
09/23/2025
211358
7491937.03
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
09/16/2025
226382
7323367.15
10b5-1 Sales for ANDREW BIALECKI
125 Summer Street, 6th Floor
Boston
MA
02110
Common
09/09/2025
220481
7046657.10
12/02/2025
05/20/2025
/s/ Andrew Bialecki