Ambiq Micro, Inc.
Ambiq Micro, Inc. (AMBQ) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · AMBQ · as of Sep 30, 2025
Ownership Breakdown
72
Institutional Holders
▲ 72 vs Q2
$134.58M
Total Inst. Value
▲ $134.58M vs Q2
21.38M
Shares Outstanding
freeFloat 77.01%
4.51M
13F Shares Held
▲ 4.51M vs Q2
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
AMBQ largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
ATREIDES MANAGEMENT, LP semiconductors & related devices | 684.3K | 5.49% | 5.49% | $20.47B | Nov 14, 2025 | NEW |
ALLIANCEBERNSTEIN L.P. semiconductors & related devices | 436.2K | 3.50% | 3.50% | $13.05B | Nov 14, 2025 | NEW |
KADENSA CAPITAL LTD semiconductors & related devices | 395.0K | 3.17% | 3.17% | $11.82B | Nov 14, 2025 | NEW |
VANGUARD GROUP INC semiconductors & related devices | 307.8K | 2.47% | 2.47% | $9.21B | Nov 7, 2025 | NEW |
BLACKROCK, INC. semiconductors & related devices | 291.9K | 2.34% | 2.34% | $8.73B | Nov 12, 2025 | NEW |
SCHONFELD STRATEGIC ADVISORS LLC semiconductors & related devices | 274.1K | 2.20% | 2.20% | $8.20B | Nov 14, 2025 | NEW |
MONASHEE INVESTMENT MANAGEMENT LLC semiconductors & related devices | 200.0K | 1.60% | 1.60% | $5.98B | Nov 12, 2025 | NEW |
SILVERCREST ASSET MANAGEMENT GROUP LLC semiconductors & related devices | 188.7K | 1.51% | 1.51% | $5.65B | Nov 14, 2025 | NEW |
FORTRESS INVESTMENT GROUP LLC semiconductors & related devices | 150.0K | 1.20% | 1.20% | $4.49B | Nov 14, 2025 | NEW |
SOFTBANK GROUP CORP. semiconductors & related devices | 148.9K | 1.19% | 1.19% | $4.46B | Nov 14, 2025 | NEW |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
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
AMBQ insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
9
Buy transactions
24
Sell transactions
0.38
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 |
|---|---|---|---|---|---|---|---|
Chen Timothy director | May 27, 2026 | Sale | 22,414 | $78.85 | $1.77M | 48.2K | Form 4 ↗ |
Chen Timothy director | May 27, 2026 | Sale | 24,248 | $79.72 | $1.93M | 23.9K | Form 4 ↗ |
Chen Timothy director | May 27, 2026 | Sale | 20,666 | $80.61 | $1.67M | 3.3K | Form 4 ↗ |
Chen Timothy director | May 27, 2026 | Sale | 3,264 | $81.57 | $266.2K | 0 | Form 4 ↗ |
Chen Timothy director | Jul 31, 2025 | C-Conversion | 70,592 | — | — | 70.6K | Form 4 ↗ |
Chen Timothy director | Jul 31, 2025 | C-Conversion | 1,707,853 | — | — | 0 | Form 4 ↗ |
Winzeler Jeffrey G Chief Financial Officer | May 14, 2026 | Sale | 25,918 | $69.90 | $1.81M | 94.5K | Form 4 ↗ |
Winzeler Jeffrey G Chief Financial Officer | May 14, 2026 | Sale | 82 | $70.65 | $5.8K | 94.4K | Form 4 ↗ |
Hanson Scott McLean Chief Technology Officer | May 14, 2026 | Sale | 3,900 | $68.62 | $267.6K | 209.4K | Form 4 ↗ |
Hanson Scott McLean Chief Technology Officer | May 14, 2026 | Sale | 6,100 | $69.59 | $424.5K | 203.3K | 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
Ambiq Micro, Inc. (AMBQ) is primarily owned by institutional investors, who hold approximately 21.1% of total shares outstanding. Company insiders own approximately 22.99%, while retail and public investors account for the remaining 55.92%.
The largest institutional shareholder of Ambiq Micro, Inc. is ATREIDES MANAGEMENT, LP, holding approximately 684,307 shares — equal to 5.49% of outstanding shares — as of September 30, 2025.
A total of 72 institutional investors currently hold AMBQ stock, with a combined institutional value of approximately $134,582,634 as of the most recent 13F filing period.
Frequently asked questions
AMBQ ownershipAmbiq Micro, Inc. (AMBQ) is primarily owned by institutional investors, who hold approximately 21.1% of shares. The largest shareholder is ATREIDES MANAGEMENT, LP with a 5.49% stake. Company insiders hold 22.99%. Data sourced from SEC Form 13F as of September 30, 2025.