Ambrx Biopharma Inc.
Ambrx Biopharma Inc. (AMAM) Insider Trading
Form 4 buy vs sell counts, ratio, and sentiment — switch this quarter or last 12 months; chart and transactions below.
SEC EDGAR · FMP · AMAM · as of Jun 9, 2026
Activity summary
Buy transactions
15
P-Purchase only
Sell transactions
0
12 Months
Buy/Sell ratio
∞
Buy/Sell (by trades)
Overall sentiment
Ambrx Biopharma Inc. insiders have been net buyers of shares over the past 12 Months, which may signal confidence in the company's outlook.
▸ Source: SEC EDGAR · Form 3 & 4 · via Financial Modeling Prep · Buy = P-Purchase only · Sell = S-Sale only
As of Jun 9, 2026
AMAM insider buying and selling by quarter
AMAM insider selling · AMAM insider buying stocks · quarterly insider activity
Mobile shows last 4Q · Desktop shows full 8Q
▸ Source: SEC EDGAR · Form 3 & 4 · via Financial Modeling Prep · last 8 quarters
As of Jun 9, 2026
Recent insider transactions
AMAM executive sell shares · AMAM board member insider trading · AMAM insider trading SEC filing
Scroll horizontally to see all columns
| Date | Insider | Type | Shares | Value | Filing |
|---|---|---|---|---|---|
| Dec 11, 2023 | O'Connor Daniel J. President and CEO · Director | Award | 750,000 | — | Form 4 |
| Oct 27, 2023 | O'Connor Daniel J. President and CEO · Director | Sale | 50,012 | $491K | Form 4 |
| Oct 23, 2023 | Cormorant Asset Management, LP 10 percent owner | Purchase | 1,307,311 | $9.14M⚡ | Form 4 |
O'Connor Daniel J.
President and CEO · Director
Date
Dec 11
Shares
750,000
Price
—
Value
—
O'Connor Daniel J.
President and CEO · Director
Date
Oct 27
Shares
50,012
Price
$9.82
Value
$491K
Cormorant Asset Management, LP
10 percent owner
Date
Oct 23
Shares
1,307,311
Price
$6.99
Value
$9.14M ⚡
▸ Source: SEC EDGAR · Form 4 filings · ⚡ = value ≥ $1M · Award/Option price shows —
About AMAM insider trading
AMAM insider trades
Ambrx Biopharma Inc. (AMAM) insider trading data is sourced from SEC Form 4 filings submitted by corporate insiders, including AMAM. Over the past 12 months, 0 insiders have filed transactions with the SEC. AMAM insiders have been primarily buying, which may reflect pre-scheduled Rule 10b5-1 plan executions.
For Ambrx Biopharma Inc.'s institutional ownership breakdown and insider ownership percentage, see the Ownership tab → Ownership tab →
Frequently asked questions
AMAM insider trading · 5 questionsThe insiders of Ambrx Biopharma Inc. (AMAM) include executives and directors such as AMAM, among others. Over the past 12 months, 0 insiders have filed Form 4 transactions with the SEC. Insider transactions are required to be reported within 2 business days of the trade date.
▸ Source: FMP /stable/insider-trading/search · SEC EDGAR Form 3 & 4 · acquisitionOrDisposition A=Buy, D=Sell · RSU vesting (M-Exempt) excluded from sentiment bar · As of Jun 9, 2026