SCHEDULE Filed 2025-01-15 Event 2025-01-13 SEC 0001213900-25-003855 →

SPRINGER TIMOTHY A → Cartesian Therapeutics, Inc. RNAC

Stake: 36.90% Shares: 9,555,394 CUSIP: 816212302 Class: Common Stock, $0.0001 par value per share

Item 4 — Purpose of Transaction

N/A

Insider Activity (last 365d)

2 transactions

0 buys · 0 sales · 2 awards/exercises

Issuer Cluster

16 13D/G filings on this issuer

15 other filings besides this one

Filer Track Record

10 filings by this filer

9 other filings in the data moat

Short Interest · settle 2026-07-15

DTC 12.30

1,925,634 shares short · +2.1% vs prior

Held by elite portfolio managers

1 holder · $244K

Point72 Asset Mgmt

+1 day

-1.7%

+5 days

+8.3%

+30 days

+3.2%

+60 days

-13.8%

+90 days

-29.1%

+180 days

-28.8%

Anchor price 18.33 on closest trading day on/after 2025-01-13. Source: Yahoo Finance daily adj_close (split + dividend adjusted).

Date	Insider	Role	Type	Shares	Price	Value
2026-04-02	Hoge Elizabeth	10%+ owner	Option exercise	758,001	—	—
2026-04-02	Kalayoglu Murat	10%+ owner	Option exercise	758,001	—	—

Filed	Form	Filer	Stake	Shares
2026-04-02	SCHEDULE 13D/A	Kalayoglu Murat	19.90%	5,833,971	view →
2024-10-15	SC	Kalayoglu Murat	—	—	view →
2024-07-05	SC	SPRINGER TIMOTHY A	—	—	view →
2024-04-12	SC	SPRINGER TIMOTHY A	—	—	view →
2021-12-27	SC	SPRINGER TIMOTHY A	—	—	view →
2021-05-27	SC	SPRINGER TIMOTHY A	—	—	view →
2020-10-23	SC	SPRINGER TIMOTHY A	—	—	view →
2020-10-15	SC	SPRINGER TIMOTHY A	—	—	view →
2020-02-05	SC	ORBIMED ADVISORS LLC	—	—	view →
2020-01-02	SC	SPRINGER TIMOTHY A	—	—	view →
2019-12-17	SC	SPRINGER TIMOTHY A	—	—	view →
2019-11-13	SC	ORBIMED ADVISORS LLC	—	—	view →
2019-02-04	SC	Polaris Venture Partners V, L.P.	—	—	view →
2018-05-03	SC	Polaris Venture Partners V, L.P.	—	—	view →
2018-01-26	SC	ORBIMED ADVISORS LLC	—	—	view →

Filed	Form	Issuer	Stake	Shares
2025-02-10	SCHEDULE	Tectonic Therapeutic, Inc. TECX	29.20%	4,226,058	view →
2024-07-05	SC	Cartesian Therapeutics, Inc. RNAC	—	—	view →
2024-04-12	SC	Cartesian Therapeutics, Inc. RNAC	—	—	view →
2021-12-27	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →
2021-05-27	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →
2020-10-23	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →
2020-10-15	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →
2020-01-02	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →
2019-12-17	SC	SELECTA BIOSCIENCES INC RNAC	—	—	view →

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