STOCK TITAN

Ten percent owner of Sensei Biotherapeutics (SNSE) sells 25,000 shares in open market

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Sensei Biotherapeutics, Inc. ten percent owner James Peyer reported open-market sales of 25,000 shares of Common Stock. The sales occurred on June 1, 2026 in two transactions: 24,524 shares at $20.00 per share and 476 shares at $21.14 per share.

After these transactions, he continued to hold more than 130,000 shares of Common Stock directly. A footnote explains that one reported price reflects a weighted average for trades executed in a range from $20.00 to $21.00, with detailed breakdowns available upon request.

Positive

  • None.

Negative

  • None.

Insights

Ten percent holder records a moderate net sale but retains a large stake.

Ten percent owner James Peyer reported open-market sales totaling 25,000 shares of Sensei Biotherapeutics Common Stock on June 1, 2026, at prices between $20.00 and $21.14 per share. These are straightforward open-market transactions using code S.

Following the sales, he still holds over 130,000 shares directly, indicating a continuing sizable position. The filing notes a weighted average price within a $20.00–$21.00 range and offers full price breakdowns on request, but does not mention any trading plan or derivatives, so the signal appears limited and routine.

Insider Peyer James
Role null
Sold 25,000 shs ($501K)
Type Security Shares Price Value
Sale Common Stock 24,524 $20.00 $490K
Sale Common Stock 476 $21.14 $10K
Holdings After Transaction: Common Stock — 130,618 shares (Direct, null)
Footnotes (1)
  1. [object Object]
Total shares sold 25,000 shares Net open-market sales on June 1, 2026
First sale tranche 24,524 shares at $20.00/share Common Stock open-market sale
Second sale tranche 476 shares at $21.14/share Common Stock open-market sale
Shares held after transaction 130,142 shares Direct Common Stock holding following one reported sale
Price range referenced $20.00–$21.00 Weighted average sale price range in footnote
open-market sale financial
"transaction_action": "open-market sale""
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
ten percent owner regulatory
""is_ten_percent_owner": 1"
weighted average price financial
"The price reported in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
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SEC Form 4
FORM 4UNITED 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
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
X
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Peyer James

(Last)(First)(Middle)
228 PARK AVENUE S.
#66643

(Street)
NEW YORK NEW YORK 10003

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Sensei Biotherapeutics, Inc. [ SNSE ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
DirectorX10% Owner
Officer (give title below)XOther (specify below)
See remarks below
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/01/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)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)
CodeVAmount(A) or (D)Price
Common Stock06/01/2026S24,524D$20(1)130,618D
Common Stock06/01/2026S476D$21.14130,142D
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 (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)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 (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (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: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. The price reported in Column 4 is a weighted average price. The prices sold ranged from $20.00 to $21.00. The reporting person will provide the issuer, any security holder of the issuer, or the SEC staff, upon request, full information regarding the number of shares sold at each separate price within the range.
/s/ James Peyer06/01/2026
** Signature of Reporting PersonDate
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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did James Peyer report for Sensei Biotherapeutics (SNSE)?

James Peyer reported selling 25,000 shares of Sensei Biotherapeutics Common Stock in open-market transactions. The sales occurred on June 1, 2026, and were split into two trades at prices of $20.00 and $21.14 per share, respectively.

At what prices did James Peyer sell SNSE shares in this Form 4 filing?

He sold 24,524 Sensei Biotherapeutics shares at $20.00 per share and 476 shares at $21.14 per share. A footnote states one reported price is a weighted average within a $20.00 to $21.00 trading range, with detailed breakdowns available on request.

How many Sensei Biotherapeutics (SNSE) shares did James Peyer sell in total?

He sold a total of 25,000 shares of Sensei Biotherapeutics Common Stock. The Form 4 transaction summary classifies this as net-sell activity, with two separate open-market sale transactions reported for the same date and no corresponding purchases or derivative exercises.

Does James Peyer still hold SNSE shares after the reported sales?

Yes. After the reported open-market sales, the Form 4 shows that James Peyer continues to hold more than 130,000 shares of Sensei Biotherapeutics Common Stock directly. This indicates he remains a significant shareholder despite the 25,000-share net sale.

What does the weighted average price footnote mean in the SNSE Form 4?

The footnote explains that the reported sale price is a weighted average of multiple trades executed between $20.00 and $21.00. It states the reporting person will provide full details on the number of shares sold at each specific price within this range upon request.