=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-09-29
10b5-1 Pre-arranged Plan: Yes
--- Issuer ---
Name: Cerebras Systems Inc. (CBRS)
CIK: 0002021728
--- Reporting Owner ---
Name: Mallick Dhiraj
CIK: 0002039572
Role: Officer (Chief Operating Officer)
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Class A Common Stock
Date: 2026-09-29 | Code: C (Conversion of derivative)
Shares: +276,000 | Price: $0.00
Shares Owned After: 396,000 | Ownership: D (Direct)
Footnotes:
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[Transaction #2]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -598 | Price: $212.93
Total Value: $127,332.14
Shares Owned After: 395,402 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F3] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $212.92 to $212.94, inclusive. Upon request by the staff of the Securities and
Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #3]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -18,274 | Price: $212.20
Total Value: $3,877,742.80
Shares Owned After: 377,128 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F4] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $211.81 to $212.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #4]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -41,391 | Price: $211.29
Total Value: $8,745,504.39
Shares Owned After: 335,737 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F5] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $210.81 to $211.81, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #5]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -46,427 | Price: $210.27
Total Value: $9,762,205.29
Shares Owned After: 289,310 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F6] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $209.81 to $210.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #6]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -41,278 | Price: $209.33
Total Value: $8,640,723.74
Shares Owned After: 248,032 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F7] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $208.81 to $209.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #7]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -20,714 | Price: $208.38
Total Value: $4,316,383.32
Shares Owned After: 227,318 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F8] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $207.81 to $208.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #8]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -9,652 | Price: $207.06
Total Value: $1,998,543.12
Shares Owned After: 217,666 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F9] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $206.68 to $207.67, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #9]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -9,047 | Price: $206.13
Total Value: $1,864,858.11
Shares Owned After: 208,619 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F10] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $205.67 to $206.66, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #10]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -8,729 | Price: $205.17
Total Value: $1,790,928.93
Shares Owned After: 199,890 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F11] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $204.65 to $205.64, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #11]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -27,492 | Price: $204.17
Total Value: $5,613,041.64
Shares Owned After: 172,398 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F12] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $203.65 to $204.65, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #12]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -9,682 | Price: $203.37
Total Value: $1,969,028.34
Shares Owned After: 162,716 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F13] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $202.63 to $203.61, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #13]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -5,637 | Price: $201.91
Total Value: $1,138,166.67
Shares Owned After: 157,079 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F14] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $201.44 to $202.39, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #14]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -22,915 | Price: $200.96
Total Value: $4,604,998.40
Shares Owned After: 134,164 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F15] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $200.42 to $201.41, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #15]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -17,848 | Price: $199.89
Total Value: $3,567,636.72
Shares Owned After: 116,316 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F16] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $199.42 to $200.37, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #16]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -17,000 | Price: $198.96
Total Value: $3,382,320.00
Shares Owned After: 99,316 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F17] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $198.42 to $199.41, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #17]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -5,170 | Price: $197.85
Total Value: $1,022,884.50
Shares Owned After: 94,146 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F18] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $197.41 to $198.40, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #18]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -6,613 | Price: $197.05
Total Value: $1,303,091.65
Shares Owned After: 87,533 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F19] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $196.41 to $197.40, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #19]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -18,703 | Price: $195.56
Total Value: $3,657,558.68
Shares Owned After: 68,830 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F20] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $195.27 to $195.96, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
[Transaction #20]
Security: Class A Common Stock
Date: 2026-09-29 | Code: S (Open market sale)
Shares: -68,830 | Price: $194.91
Total Value: $13,415,655.30
Shares Owned After: 0 | Ownership: D (Direct)
Footnotes:
[F2] The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
[F21] The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $194.27 to $195.26, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
--- Derivative Transactions ---
[Transaction #1]
Security: Stock Option
Date: 2026-09-29 | Code: M (Exercise of derivative)
Shares: -276,000 | Price: $0.00
Exercise Price: $0.98
Exercisable: N/A | Expires: 2028-07-16
Shares Owned After: 91,370 | Ownership: D (Direct)
Footnotes:
[F22] The stock option is fully vested and exercisable.
[Transaction #2]
Security: Class B Common Stock
Date: 2026-09-29 | Code: M (Exercise of derivative)
Shares: +276,000 | Price: $0.00
Shares Owned After: 796,807 | Ownership: D (Direct)
Footnotes:
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[Transaction #3]
Security: Class B Common Stock
Date: 2026-09-29 | Code: C (Conversion of derivative)
Shares: -276,000 | Price: $0.00
Shares Owned After: 520,807 | Ownership: D (Direct)
Footnotes:
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
[F1] The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
--- Footnotes (Complete Index) ---
F1: The Class B Common Stock is convertible into an equal number of Class A Common Stock at any time, at the Reporting Person's election, and has no expiration date.
F10: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $205.67 to $206.66, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F11: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $204.65 to $205.64, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F12: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $203.65 to $204.65, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F13: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $202.63 to $203.61, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F14: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $201.44 to $202.39, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F15: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $200.42 to $201.41, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F16: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $199.42 to $200.37, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F17: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $198.42 to $199.41, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F18: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $197.41 to $198.40, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F19: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $196.41 to $197.40, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F2: The sale reported on this Form 4 represents shares sold by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026
F20: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $195.27 to $195.96, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F21: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $194.27 to $195.26, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F22: The stock option is fully vested and exercisable.
F3: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $212.92 to $212.94, inclusive. Upon request by the staff of the Securities and
Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F4: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $211.81 to $212.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F5: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $210.81 to $211.81, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F6: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $209.81 to $210.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F7: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $208.81 to $209.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F8: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $207.81 to $208.80, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F9: The sale price reported in Column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $206.68 to $207.67, inclusive. Upon request by the staff of the Securities and Exchange commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
--- Signature ---
/s/ /s/ Robert Mills, Attorney-in-fact (2026-09-30)
