STOCK TITAN

AWM trims 908 Devices (MASS) holdings with 78,209-share open-market sale

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

Rhea-AI Filing Summary

AWM Investment Company, Inc., a ten percent owner of 908 Devices Inc., reported indirect open-market sales of the company’s common stock through a limited partnership. Across four transactions on May 6–8, AWM-related funds sold a total of 78,209 shares at prices around $8 per share.

Individual trades included 5,000 shares at $8.00, 57,365 shares at $8.0564, 12,819 shares at $8.2042, and 3,025 shares at $8.20. After these sales, AWM, as investment adviser to several funds, reports indirect ownership of 5,121,715 shares and disclaims beneficial ownership except for its pecuniary interest.

Positive

  • None.

Negative

  • None.
Insider AWM Investment Company, Inc.
Role null
Sold 78,209 shs ($632K)
Type Security Shares Price Value
Sale 908 DEVICES, INC. 3,025 $8.20 $25K
Sale 908 DEVICES, INC. 12,819 $8.2042 $105K
Sale 908 DEVICES, INC. 5,000 $8.00 $40K
Sale 908 DEVICES, INC. 57,365 $8.0564 $462K
Holdings After Transaction: 908 DEVICES, INC. — 5,121,715 shares (Indirect, By Limited Partnership)
Footnotes (1)
  1. This is a weighted average price. AWM Investment Company, Inc., a Delaware Corporation (AWM), is the investment adviser to Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (CAY), Special Situations Private Equity Fund, L.P. (SSPE), Special Situations Technology Fund, L.P. (TECH) and Special Situations Technology Fund II, L.P. (TECH II and together with SSFQP, CAY, SSPE and TECH, the Funds). As the investment adviser to the Funds, AWM holds sole voting and investment power over 2,182,852 shares of Common Stock of the Issuer (the Shares) held by SSFQP, 631,513 Shares held by CAY, 291,890 Shares held by SSPE, 338,137 Shares held by TECH and 1,677,323 Shares held by TECH II. David M. Greenhouse (Greenhouse) and Adam C. Stettner (Stettner) are the controlling principals of AWM. The reporting person disclaims beneficial ownership of the Shares, except to the extent of its pecuniary interest therein. This report shall not be deemed an admission that the reporting person is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
Total shares sold 78,209 shares Open-market sales on May 6–8
Post-transaction holdings 5,121,715 shares Indirect ownership after May 8 sale
Sale price May 8 $8.20 per share 3,025 shares sold on May 8
Sale price May 7 $8.2042 per share 12,819 shares sold on May 7
Sale price May 6 (larger trade) $8.0564 per share 57,365 shares sold on May 6
Sale price May 6 (smaller trade) $8.00 per share 5,000 shares sold on May 6
Shares held by SSFQP 2,182,852 shares Held by Special Situations Fund III QP, L.P.
Shares held by TECH II 1,677,323 shares Held by Special Situations Technology Fund II, L.P.
open-market sale financial
"transaction_action is described as "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.
indirect ownership financial
"transactions list ownership_type as indirect and nature as By Limited Partnership"
pecuniary interest financial
"the reporting person disclaims beneficial ownership ... except to the extent of its pecuniary interest therein"
beneficial ownership financial
"the reporting person disclaims beneficial ownership of the Shares"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
Section 16 regulatory
"for purposes of Section 16 of the Securities Exchange Act of 1934"
Section 16 is a U.S. securities law rule that governs the trading and disclosure obligations of company insiders — typically officers, directors and large shareholders — to promote transparency and deter unfair profit-taking. It requires insiders to publicly report their stock trades and allows companies or the issuer to reclaim quick, short-term profits from certain insider trades, like a scoreboard and a refund policy that help investors see and limit possible insider advantage.
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
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*
AWM Investment Company, Inc.

(Last)(First)(Middle)
527 MADISON AVENUE
SUITE 2600

(Street)
NEW YORK NEW YORK 10022

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
908 Devices Inc. [ MASS ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
DirectorX10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/06/2026
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
908 DEVICES, INC.05/06/2026S5,000D$85,194,924IBy Limited Partnership
908 DEVICES, INC.05/06/2026S57,365D$8.0564(1)5,137,559IBy Limited Partnership
908 DEVICES, INC.05/07/2026S12,819D$8.2042(1)5,124,740IBy Limited Partnership
908 DEVICES, INC.05/08/2026S3,025D$8.2(1)5,121,715(2)(3)I(2)(3)By Limited Partnership(2)(3)
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. This is a weighted average price.
2. AWM Investment Company, Inc., a Delaware Corporation (AWM), is the investment adviser to Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (CAY), Special Situations Private Equity Fund, L.P. (SSPE), Special Situations Technology Fund, L.P. (TECH) and Special Situations Technology Fund II, L.P. (TECH II and together with SSFQP, CAY, SSPE and TECH, the Funds). As the investment adviser to the Funds, AWM holds sole voting and investment power over 2,182,852 shares of Common Stock of the Issuer (the Shares) held by SSFQP, 631,513 Shares held by CAY, 291,890 Shares held by SSPE, 338,137 Shares held by TECH and 1,677,323 Shares held by TECH II.
3. David M. Greenhouse (Greenhouse) and Adam C. Stettner (Stettner) are the controlling principals of AWM. The reporting person disclaims beneficial ownership of the Shares, except to the extent of its pecuniary interest therein. This report shall not be deemed an admission that the reporting person is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
Adam Stettner05/08/2026
** 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 did AWM Investment Company report in this Form 4 for MASS?

AWM reported that funds it advises executed open-market sales of 908 Devices Inc. common stock. Over four trades between May 6 and May 8, they sold a combined 78,209 shares at prices slightly above $8 per share, reducing their indirect holdings.

How many 908 Devices (MASS) shares were sold and at what prices?

The filing shows sales totaling 78,209 shares. Reported trades were 5,000 shares at $8.00, 57,365 shares at $8.0564, 12,819 shares at $8.2042, and 3,025 shares at $8.20, all described as open-market sales.

How many 908 Devices shares does AWM report owning after these sales?

After the reported transactions, AWM reports indirect ownership of 5,121,715 shares of 908 Devices common stock. These shares are held by several investment funds for which AWM serves as investment adviser, and AWM disclaims beneficial ownership beyond its pecuniary interest.

Were the 908 Devices (MASS) sales direct or indirect for AWM?

All reported transactions are classified as indirect, with the nature of ownership listed as “By Limited Partnership.” The shares are held by multiple investment funds advised by AWM, rather than directly by AWM itself or by individual principals named in the footnotes.

Which AWM-advised funds hold 908 Devices shares according to the filing?

Footnotes state that AWM advises SSFQP, CAY, SSPE, TECH, and TECH II. These funds hold 2,182,852; 631,513; 291,890; 338,137; and 1,677,323 shares respectively, giving AWM sole voting and investment power over those positions through its role as investment adviser.

Does AWM claim beneficial ownership of the MASS shares it advises?

The filing explains that AWM disclaims beneficial ownership of the 908 Devices shares, except to the extent of its pecuniary interest. It also notes that this report should not be deemed an admission that AWM is the beneficial owner of the securities for Section 16 purposes.