STOCK TITAN

Director in Rapid Micro Biosystems (RPID) buys shares and new warrants

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Rapid Micro Biosystems director Kirk Malloy increased his stake through a registered direct offering. On May 29, 2026, he purchased 12,787 shares of Class A Common Stock together with an accompanying Series A Warrant and Series B Warrant, each to buy 12,787 additional shares, for a combined purchase price of $1.955 per share plus both warrants.

Following the transactions, Malloy holds 60,687 shares directly and 10,000 shares indirectly through a family trust. The Series A Warrant is exercisable at $1.955 per share from November 29, 2026 until May 29, 2027, and the Series B Warrant at $2.340 per share from November 29, 2026 until May 29, 2031. Both warrants include a 4.99% beneficial ownership cap on exercise.

Positive

  • None.

Negative

  • None.
Insider Malloy Kirk
Role null
Type Security Shares Price Value
Grant/Award Series A Warrant (right to buy) 12,787 $0.00 --
Grant/Award Series B Warrant (right to buy) 12,787 $0.00 --
Grant/Award Class A Common Stock 12,787 $1.955 $25K
holding Class A Common Stock -- -- --
Holdings After Transaction: Series A Warrant (right to buy) — 12,787 shares (Direct, null); Series B Warrant (right to buy) — 12,787 shares (Direct, null); Class A Common Stock — 60,687 shares (Direct, null); Class A Common Stock — 10,000 shares (Indirect, By Trust)
Footnotes (1)
  1. On May 29, 2026, the Reporting Person purchased, in a registered direct offering, 12,787 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each share of Issuer Class A Common Stock and accompanying Series A and Series B Warrant was $1.955. The issuance of such securities was approved by the Issuer's compensation committee of the board of directors in accordance with Rule 16(b)-3 of the Securities Exchange Act of 1934, as amended. Shares held in family trust as to which the Reporting Person shares investment power and the Reporting Person and/or immediate family members are beneficiaries. The Series A and Series B Warrants cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 4.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.
Common shares purchased 12,787 shares Purchased in registered direct offering on May 29, 2026
Unit purchase price $1.955 per share plus Series A and B Warrants Price per stock-and-warrants unit
Direct holdings after transaction 60,687 shares Class A Common Stock held directly after May 29, 2026
Indirect trust holdings 10,000 shares Family trust holdings with shared investment power
Series A Warrant size 12,787 underlying shares Exercise price $1.955; exercisable Nov 29, 2026–May 29, 2027
Series B Warrant size 12,787 underlying shares Exercise price $2.340; exercisable Nov 29, 2026–May 29, 2031
Beneficial ownership cap 4.99% Maximum ownership allowed upon warrant exercise
registered direct offering financial
"purchased, in a registered direct offering, 12,787 shares of the Issuer's Class A Common Stock"
A registered direct offering is a way for a company to sell new shares of its stock directly to select investors with regulatory approval. This method allows the company to raise funds quickly and efficiently without needing a public auction, similar to offering exclusive access to a limited number of buyers. For investors, it often provides an opportunity to purchase shares at a favorable price, while giving the company immediate access to capital.
Series A Warrant financial
"an accompanying Series A Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock"
A Series A warrant is a contract issued alongside a company’s early funding round that gives the holder the right to buy a set number of shares later at a fixed price. Think of it like a coupon that lets an investor purchase stock at today’s agreed price even if the company’s value rises; it can boost potential upside for the warrant holder and create dilution for existing shareholders, so investors watch them when assessing ownership and future share value.
Series B Warrant financial
"an accompanying Series B Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock"
A Series B warrant is a tradable right issued alongside a Series B funding round that lets its holder buy a specified number of company shares at a fixed price for a set period. It matters to investors because exercising the warrant increases the total shares outstanding (dilution) and can be a cheap way to gain ownership if the company’s value rises — think of it like a coupon to buy stock later at today’s price.
Rule 16(b)-3 regulatory
"approved by the Issuer's compensation committee of the board of directors in accordance with Rule 16(b)-3"
beneficially own more than 4.99% financial
"would beneficially own more than 4.99% of the total number of shares of the Issuer's Class A Common Stock"
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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
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*
Malloy Kirk

(Last)(First)(Middle)
C/O RAPID MICRO BIOSYSTEMS, INC.
25 HARTWELL AVENUE

(Street)
LEXINGTON MASSACHUSETTS 02421

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
RAPID MICRO BIOSYSTEMS, INC. [ RPID ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/29/2026
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
Class A Common Stock05/29/2026A(1)12,787A$1.95560,687D
Class A Common Stock10,000IBy Trust(2)
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
Series A Warrant (right to buy)$1.95505/29/2026A(1)12,78711/29/2026(3)05/29/2027Class A Common Stock12,787$0(1)12,787D
Series B Warrant (right to buy)$2.3405/29/2026A(1)12,78711/29/2026(3)05/29/2031Class A Common Stock12,787$0(1)12,787D
Explanation of Responses:
1. On May 29, 2026, the Reporting Person purchased, in a registered direct offering, 12,787 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 12,787 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each share of Issuer Class A Common Stock and accompanying Series A and Series B Warrant was $1.955. The issuance of such securities was approved by the Issuer's compensation committee of the board of directors in accordance with Rule 16(b)-3 of the Securities Exchange Act of 1934, as amended.
2. Shares held in family trust as to which the Reporting Person shares investment power and the Reporting Person and/or immediate family members are beneficiaries.
3. The Series A and Series B Warrants cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 4.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.
Remarks:
/s/ Sean M. Wirtjes, Attorney-in-Fact for Kirk Malloy06/02/2026
** 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 Kirk Malloy acquire in the latest Form 4 for RPID?

Kirk Malloy acquired 12,787 shares of Class A Common Stock plus Series A and Series B Warrants for 12,787 shares each, all at a combined price of $1.955 per share and accompanying warrants in a registered direct offering approved by the compensation committee.

How many Rapid Micro Biosystems (RPID) shares does Kirk Malloy now hold?

After the reported transactions, Kirk Malloy holds 60,687 Class A Common Stock shares directly and 10,000 shares indirectly through a family trust. The trust holdings are shared-investment-power positions where Malloy and/or immediate family members are beneficiaries according to the disclosure.

What are the key terms of the Series A Warrant reported for RPID?

The Series A Warrant covers 12,787 shares of Class A Common Stock at an exercise price of $1.955 per share. It becomes exercisable on November 29, 2026 and expires on May 29, 2027, with a 4.99% beneficial ownership limitation on exercises.

What are the key terms of the Series B Warrant reported for RPID?

The Series B Warrant also covers 12,787 Class A Common Stock shares at an exercise price of $2.340 per share. It is exercisable starting November 29, 2026 and expires on May 29, 2031, subject to the same 4.99% beneficial ownership cap.

How was the purchase price structured for Kirk Malloy’s RPID securities?

The purchase price was $1.955 for each share of Class A Common Stock together with an accompanying Series A Warrant and Series B Warrant, or pre-funded warrants in lieu of shares. This combined price applied per share-plus-warrants unit in the registered direct offering.

What is the 4.99% beneficial ownership limitation mentioned in the RPID Form 4?

The Series A and Series B Warrants cannot be exercised if doing so would cause the holder and affiliated entities to beneficially own more than 4.99% of Rapid Micro Biosystems’ Class A Common Stock immediately after exercise, limiting concentration of ownership from warrant exercises.