SEC ownership of Cartesian Therapeutics, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001453687.
- CIK
- 0001453687
- Symbol
- RNAC on Nasdaq
- Location
- Frederick, MD
- Parsed ownership evidence
- 13D/G, 3/4/5, and 13F
- Lead holder
- Timothy A. Springer
- 13D/G signal
- Timothy A. Springer
- Latest evidence date
- 31 Mar 2026
Ownership snapshot
Top shareholders of Cartesian Therapeutics, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Lead holder
Timothy A. Springer
13D/G signal
Timothy A. Springer
Evidence rows
50
Latest as of
31 Mar 2026
13D/G
3/4/5
13F
Lead comparable stake: 37%
13D/G row: Timothy A. Springer
Showing first 8 of 50 holder rows.
Open remaining rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Timothy A. Springer |
13D/G
3/4/5
Director, 10%+ Owner
|
37%
|
$116,671,361
9,555,394 shares
|
+$258,583 | 13 Jan 2025 |
| Murat Kalayoglu |
13D/G
3/4/5
10%+ Owner
|
20%
|
$48,188,600
5,833,971 shares
|
$0 | 31 Mar 2026 |
| Squarepoint Ops LLC |
13D/G
13F
Company
|
8.3%
|
$14,163,542
2,209,601 shares
|
$0 | 09 Mar 2026 |
| JPMORGAN CHASE & CO |
13D/G
13F
Company
|
6.1%
|
$20,459,516
1,675,636 shares
|
$0 | 31 Mar 2025 |
| FMR LLC |
13D/G
13F
Company
|
3%
|
$4,990,396
799,743 shares
|
-$3,539,615 | 31 Mar 2026 |
| BlackRock, Inc. |
13F
Company
|
2.2%
|
$3,684,515
599,108 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
1.5%
|
$2,506,722
407,597 shares
|
— | 31 Mar 2026 |
| 683 Capital Management, LLC |
13F
Company
|
1.2%
|
$2,029,500
330,000 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$52,874.
Buys
$205,797
Insiders: 1
Sells
$258,671
Insiders: 3
Net
-$52,874
Shares: -7,930
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 30,000
Shares: 37,930
| Window (months) | Buy shares | Sell shares | Buy $ | Sell $ | Net $ |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 30,000 | 37,930 | $205,797 | $258,671 | -$52,874 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Current reporting-owner rows connected to Cartesian Therapeutics, Inc.. Open the relationship link for the CIK-to-CIK filing trail.
Rows
26
Lead holder
Timothy A. Springer
Net 12M change
-$52,874
Latest report
02 Apr 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Timothy A. Springer | Director, 10%+ Owner | $81,409,176 | Mixed | 02 Jan 2026 | ||
| Murat Kalayoglu | 10%+ Owner | $41,970,235 | Mixed | 02 Apr 2026 | ||
| Seven One Eight Three Four Irrevocable Trust | 10%+ Owner | $41,964,073 | Mixed | 02 Apr 2026 | ||
| Elizabeth Hoge | 10%+ Owner | $41,964,073 | Mixed | 02 Apr 2026 | ||
| Carsten Brunn | President and CEO, Director | $2,206,377 | -$162,077 | -6.8% | Filing P/S | 06 Jan 2026 |
| Metin Kurtoglu | Chief Technology Officer | $1,110,427 | Mixed | 03 Jan 2025 | ||
| Michael Singer | Director | $1,081,194 | Mixed | 13 Mar 2026 | ||
| Peter G. Traber | Chief Medical Officer | $930,762 | Mixed | 25 Sep 2023 | ||
| Lloyd P. Johnston | Chief Operations Officer | $922,211 | Mixed | 04 Jan 2023 | ||
| Emily English | Chief Operations Officer | $835,211 | Mixed | 02 Jan 2026 | ||
| Blaine Davis | Chief Financial Officer | $826,684 | -$72,227 | -8% | Filing P/S | 06 Jan 2026 |
| Aymeric Sallin | Director | $546,800 | Mixed | 02 Jan 2024 | ||
| Timothy C. Barabe | Director | $487,524 | +$205,797 | +73% | Mixed | 02 Jan 2026 |
| Takashi Kei Kishimoto | Chief Scientific Officer | $464,151 | Mixed | 30 May 2023 | ||
| Kevin Tan | Chief Financial Officer | $427,220 | Mixed | 03 Jan 2022 | ||
| Milos Miljkovic | Chief Medical Officer | $401,134 | -$24,367 | -5.7% | Filing P/S | 06 Jan 2026 |
| Christopher M. Jewell | Chief Scientific Officer | $255,114 | Mixed | 10 Jan 2025 | ||
| ZENNER PATRICK J | Director | $115,792 | Mixed | 02 Jan 2026 | ||
| Nishan M. DeSilva | Director | $102,204 | Mixed | 02 Jan 2026 | ||
| Kemal Malik | Director | $100,235 | Mixed | 02 Jan 2026 | ||
| Goran Ando | Director | $59,250 | Mixed | 02 Jan 2023 | ||
| Carrie S. Cox | Director | $57,896 | Mixed | 02 Jan 2025 | ||
| June Ann Seymour | Chief Accounting Officer | $54,925 | Mixed | 02 Jan 2026 | ||
| Adrian Ion Bot | Director | $44,080 | Mixed | 16 Dec 2025 | ||
| Ann K. Donohue | VP Finance | $8,625 | Mixed | 27 May 2021 | ||
| Scott Dunseth Myers | Director | Mixed | 13 Nov 2023 |
Recent Insider Transactions by Companies or Individuals for Cartesian Therapeutics, Inc.
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Reported value | Reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Hoge Elizabeth | RNAC | Common Stock | Options Exercise | 16.6% | 758,001 | 5,313,261 | 02 Apr 2026 | as trustee | ||
| Elizabeth Hoge | RNAC | Common Stock | Options Exercise | 16.6% | 758,001 | 5,313,261 | 02 Apr 2026 | as trustee | ||
| Hoge Elizabeth | RNAC | Series A Non-Voting Convertible Preferred Stock | Options Exercise | -40.3% | -22,740 | 33,662 | 02 Apr 2026 | as trustee | ||
| Elizabeth Hoge | RNAC | Series A Non-Voting Convertible Preferred Stock | Options Exercise | -40.3% | -22,740 | 33,662 | 02 Apr 2026 | as trustee | ||
| Murat Kalayoglu | RNAC | Common Stock | Options Exercise | 16.6% | 758,001 | 5,313,261 | 02 Apr 2026 | by trust | ||
| Murat Kalayoglu | RNAC | Series A Non-Voting Convertible Preferred Stock | Options Exercise | -40.3% | -22,740 | 33,662 | 02 Apr 2026 | by trust | ||
| Michael Singer | RNAC | Common Stock | Gift | -11.7% | -6,555 | 49,578 | 13 Mar 2026 | Direct | ||
| Carsten Brunn | RNAC | Common Stock | Sale | -6.84% | $162,077 | $6.82 | -23,766 | 323,530 | 06 Jan 2026 | Direct |
| Milos Miljkovic | RNAC | Common Stock | Sale | -5.73% | $24,367 | $6.82 | -3,573 | 58,820 | 06 Jan 2026 | Direct |
| Blaine Davis | RNAC | Common Stock | Sale | -8.03% | $72,227 | $6.82 | -10,591 | 121,220 | 06 Jan 2026 | Direct |
| Nishan M. DeSilva | RNAC | Common Stock | Award | 29.7% | 2,600 | 11,366 | 02 Jan 2026 | Direct | ||
| Nishan M. DeSilva | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Carsten Brunn | RNAC | Common Stock | Award | 70.2% | 143,200 | 347,296 | 02 Jan 2026 | Direct | ||
| Carsten Brunn | RNAC | Employee Stock Option (right to buy) | Award | 415,700 | 415,700 | 02 Jan 2026 | Direct | |||
| Kemal Malik | RNAC | Common Stock | Award | 30.5% | 2,600 | 11,133 | 02 Jan 2026 | Direct | ||
| Kemal Malik | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Milos Miljkovic | RNAC | Common Stock | Award | 76.3% | 27,000 | 62,393 | 02 Jan 2026 | Direct | ||
| Milos Miljkovic | RNAC | Employee Stock Option (right to buy) | Award | 77,000 | 77,000 | 02 Jan 2026 | Direct | |||
| Zenner Patrick J | RNAC | Common Stock | Award | 25.1% | 2,600 | 12,974 | 02 Jan 2026 | Direct | ||
| Zenner Patrick J | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| June Ann Seymour | RNAC | Common Stock | Award | 6,500 | 6,500 | 02 Jan 2026 | Direct | |||
| June Ann Seymour | RNAC | Employee Stock Option (right to buy) | Award | 19,000 | 19,000 | 02 Jan 2026 | Direct | |||
| Blaine Davis | RNAC | Common Stock | Award | 39% | 37,000 | 131,811 | 02 Jan 2026 | Direct | ||
| Blaine Davis | RNAC | Employee Stock Option (right to buy) | Award | 109,000 | 109,000 | 02 Jan 2026 | Direct | |||
| Timothy C. Barabe | RNAC | Common Stock | Award | 4.78% | 2,600 | 56,966 | 02 Jan 2026 | Direct | ||
| Timothy C. Barabe | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Emily English | RNAC | Common Stock | Award | 34.2% | 24,000 | 94,226 | 02 Jan 2026 | Direct | ||
| Emily English | RNAC | Employee Stock Option (right to buy) | Award | 71,000 | 71,000 | 02 Jan 2026 | Direct | |||
| Michael Singer | RNAC | Common Stock | Award | 4.86% | 2,600 | 56,133 | 02 Jan 2026 | Direct | ||
| Michael Singer | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Timothy A. Springer | RNAC | Common Stock | Award | 0.03% | 2,600 | 8,646,285 | 02 Jan 2026 | Direct | ||
| Timothy A. Springer | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Murat Kalayoglu | RNAC | Common Stock | Award | 0.51% | 2,600 | 511,577 | 02 Jan 2026 | Direct | ||
| Murat Kalayoglu | RNAC | Stock Option (Right to Buy) | Award | 7,800 | 7,800 | 02 Jan 2026 | Direct | |||
| Emily English | RNAC | Common Stock | Options Exercise | 12% | 7,500 | 70,226 | 30 Dec 2025 | Direct | ||
| Emily English | RNAC | Stock Option (Right to Buy) | Options Exercise | -27.9% | -7,500 | 19,369 | 30 Dec 2025 | Direct | ||
| Adrian Ion Bot | RNAC | Common Stock | Award | 5,800 | 5,800 | 16 Dec 2025 | Direct | |||
| Adrian Ion Bot | RNAC | Stock Option (Right to Buy) | Award | 17,200 | 17,200 | 16 Dec 2025 | Direct | |||
| Timothy C. Barabe | RNAC | Common Stock | Purchase | 123.1% | $205,797 | $6.86 | 30,000 | 54,366 | 04 Dec 2025 | Direct |
| Emily English | RNAC | Common Stock | Options Exercise | 13.6% | 7,500 | 62,726 | 28 Nov 2025 | Direct | ||
| Emily English | RNAC | Stock Option (Right to Buy) | Options Exercise | -21.8% | -7,500 | 26,869 | 28 Nov 2025 | Direct | ||
| Michael Singer | RNAC | Common Stock | Gift | -27.2% | -20,000 | 53,533 | 18 Nov 2025 | Direct | ||
| June Ann Seymour | RNAC | Employee Stock Option (right to buy) | Award | 50,000 | 50,000 | 27 Oct 2025 | Direct |
An asterisk next to the price means the reported price is likely invalid.