Ambrx Biopharma Inc.
Ambrx Biopharma Inc. (AMAM) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · AMAM · as of Dec 31, 2023
Ownership Breakdown
76
Institutional Holders
▲ 16 vs Q3
$912.65M
Total Inst. Value
▲ $344.36M vs Q3
63.29M
Shares Outstanding
freeFloat 34.64%
64.09M
13F Shares Held
▲ 14.67M vs Q3
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
AMAM largest shareholders · institutional ownership
Q4 2023 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
DARWIN GLOBAL MANAGEMENT, LTD. biological products, (no diagnostic substances) | 16.69M | 26.81% | 26.81% | $237.65B | Feb 14, 2024 | NEW |
CORMORANT ASSET MANAGEMENT, LP biological products, (no diagnostic substances) | 11.23M | 18.04% | 18.04% | $159.93B | Feb 14, 2024 | NEW |
PARADIGM BIOCAPITAL ADVISORS LP biological products, (no diagnostic substances) | 4.35M | 6.99% | 6.99% | $61.98B | Feb 14, 2024 | NEW |
D. E. SHAW & CO., INC. biological products, (no diagnostic substances) | 4.24M | 6.81% | 6.81% | $60.38B | Feb 14, 2024 | NEW |
DEEP TRACK CAPITAL, LP biological products, (no diagnostic substances) | 3.71M | 5.96% | 5.96% | $52.84B | Feb 14, 2024 | NEW |
NEXTECH INVEST LTD. biological products, (no diagnostic substances) | 3.13M | 5.03% | 5.03% | $44.56B | Feb 14, 2024 | NEW |
BALYASNY ASSET MANAGEMENT L.P. biological products, (no diagnostic substances) | 2.15M | 3.46% | 3.46% | $30.68B | Feb 14, 2024 | NEW |
LOGOS GLOBAL MANAGEMENT LP biological products, (no diagnostic substances) | 2.10M | 3.37% | 3.37% | $29.90B | Feb 14, 2024 | NEW |
VR ADVISER, LLC biological products, (no diagnostic substances) | 2.07M | 3.33% | 3.33% | $29.48B | Feb 14, 2024 | NEW |
CITADEL ADVISORS LLC biological products, (no diagnostic substances) | 2.04M | 3.28% | 3.28% | $29.08B | Feb 14, 2024 | NEW |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q4 2023 vs prior quarter
Q4 2023
0
Increased
+0 shares50
New Positions
first time holders0
Decreased
−0 shares0
Sold Out
fully exitedNet shares change (top 50)
+0
+0 / −0
Net new holders
+50
50 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
AMAM insider trading · insider activity
Source: SEC Form 4
Insiders have been net buyers of shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
7
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
O'Connor Daniel J. President and CEO | Dec 11, 2023 | Award | 750,000 | — | — | 1.36M | Form 4 ↗ |
O'Connor Daniel J. President and CEO | Oct 27, 2023 | Sale | 50,012 | $9.82 | $491.1K | 342.8K | Form 4 ↗ |
Cormorant Asset Management, LP 10 percent owner | Oct 23, 2023 | Purchase | 1,307,311 | $6.99 | $9.14M | 11.23M | Form 4 ↗ |
Cormorant Asset Management, LP 10 percent owner | Sep 18, 2023 | Purchase | 751,233 | $9.24 | $6.94M | 69.47M | Form 4 ↗ |
Cormorant Asset Management, LP 10 percent owner | Sep 15, 2023 | Purchase | 1,401,505 | $9.05 | $12.68M | 68.71M | Form 4 ↗ |
DALESANDRO MARGARET director | Sep 1, 2023 | Award | 125,000 | — | — | 125.0K | Form 4 ↗ |
DALESANDRO MARGARET director | Sep 1, 2023 | Award | 70,833 | — | — | 70.8K | Form 4 ↗ |
O'Connor Daniel J. President and CEO | Jul 5, 2023 | Award | 1,216,500 | $2.38 | $2.90M | 1.22M | Form 4 ↗ |
Nelson Sonja Chief Financial Officer | Jul 5, 2023 | Award | 389,000 | $2.38 | $925.8K | 389.0K | Form 4 ↗ |
Aromando Andrew Chief Operating Officer | Jul 5, 2023 | Award | 389,000 | $2.38 | $925.8K | 389.0K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Ambrx Biopharma Inc. (AMAM) is primarily owned by institutional investors, who hold approximately 100.0% of total shares outstanding. Company insiders own approximately 65.36%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Ambrx Biopharma Inc. is DARWIN GLOBAL MANAGEMENT, LTD., holding approximately 16.69 million shares — equal to 26.81% of outstanding shares — as of December 31, 2023.
A total of 76 institutional investors currently hold AMAM stock, with a combined institutional value of approximately $912,651,263 as of the most recent 13F filing period.
Frequently asked questions
AMAM ownershipAmbrx Biopharma Inc. (AMAM) is primarily owned by institutional investors, who hold approximately 100.0% of shares. The largest shareholder is DARWIN GLOBAL MANAGEMENT, LTD. with a 26.81% stake. Company insiders hold 65.36%. Data sourced from SEC Form 13F as of December 31, 2023.