Allegro MicroSystems, Inc.
Allegro MicroSystems, Inc. (ALGM) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ALGM · as of Sep 30, 2025
Ownership Breakdown
319
Institutional Holders
▲ 15 vs Q2
$3.97B
Total Inst. Value
▼ $1.03B vs Q2
186.22M
Shares Outstanding
freeFloat 66.65%
135.92M
13F Shares Held
▼ 10.17M 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
ALGM largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
FMR LLC semiconductors & related devices | 27.47M | 14.88% | 14.88% | $802.06B | Nov 13, 2025 | ▲ 220.4K |
CAPITAL RESEARCH GLOBAL INVESTORS semiconductors & related devices | 16.82M | 9.11% | 9.11% | $491.28B | Nov 13, 2025 | ▲ 920.4K |
VANGUARD GROUP INC semiconductors & related devices | 14.29M | 7.74% | 7.74% | $417.37B | Nov 7, 2025 | ▲ 87.5K |
BLACKROCK, INC. semiconductors & related devices | 11.38M | 6.16% | 6.16% | $332.22B | Nov 12, 2025 | ▼ 412.4K |
JPMORGAN CHASE & CO semiconductors & related devices | 7.73M | 4.19% | 4.19% | $225.75B | Nov 26, 2025 | ▼ 282.2K |
INVESCO LTD. semiconductors & related devices | 5.31M | 2.88% | 2.88% | $155.12B | Nov 13, 2025 | ▼ 942.1K |
STATE STREET CORP semiconductors & related devices | 5.28M | 2.86% | 2.86% | $154.21B | Nov 14, 2025 | ▲ 88.3K |
CLEARBRIDGE INVESTMENTS, LLC semiconductors & related devices | 2.93M | 1.59% | 1.59% | $85.64B | Nov 13, 2025 | ▼ 231.0K |
ALLIANCEBERNSTEIN L.P. semiconductors & related devices | 2.69M | 1.46% | 1.46% | $78.56B | Nov 14, 2025 | ▼ 69.4K |
GEODE CAPITAL MANAGEMENT, LLC semiconductors & related devices | 2.37M | 1.28% | 1.28% | $69.19B | Nov 12, 2025 | ▼ 36.9K |
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
17
Increased
+4.83M shares2
New Positions
first time holders30
Decreased
−10.23M shares0
Sold Out
fully exitedNet shares change (top 50)
5.40M
+4.83M / −10.23M
Net new holders
-11
2 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
ALGM 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.
13
Buy transactions
15
Sell transactions
0.87
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 |
|---|---|---|---|---|---|---|---|
Madormo Richard SVP, Worldwide Sales | Jun 3, 2026 | Sale | 5,000 | $52.72 | $263.6K | 69.7K | Form 4 ↗ |
Coleman Troy SVP, General Manager, Products | May 22, 2026 | Sale | 4,500 | $45.72 | $205.7K | 77.5K | Form 4 ↗ |
Webster Roald Graham VP, Chief Accounting Officer | May 21, 2026 | Sale | 5,217 | $44.88 | $234.2K | 13.1K | Form 4 ↗ |
Hagen Erin SVP, CHRO | May 16, 2026 | Tax Withhold | 5,815 | $43.10 | $250.6K | 33.3K | Form 4 ↗ |
Kent Ian SVP, Global Operations | May 16, 2026 | Tax Withhold | 2,345 | $43.10 | $101.1K | 28.0K | Form 4 ↗ |
Kent Ian SVP, Global Operations | May 18, 2026 | Sale | 2,642 | $41.56 | $109.8K | 25.4K | Form 4 ↗ |
D'Antilio Derek EVP, CFO & Treasurer | May 16, 2026 | Tax Withhold | 37,840 | $43.10 | $1.63M | 238.8K | Form 4 ↗ |
Madormo Richard SVP, Worldwide Sales | May 16, 2026 | Tax Withhold | 5,439 | $43.10 | $234.4K | 74.7K | Form 4 ↗ |
Webster Roald Graham VP, Chief Accounting Officer | May 16, 2026 | Tax Withhold | 4,277 | $43.10 | $184.3K | 18.3K | Form 4 ↗ |
Doogue Michael President and CEO | May 16, 2026 | Tax Withhold | 60,508 | $43.10 | $2.61M | 279.1K | 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
Allegro MicroSystems, Inc. (ALGM) is primarily owned by institutional investors, who hold approximately 73.0% of total shares outstanding. Company insiders own approximately 33.35%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Allegro MicroSystems, Inc. is FMR LLC, holding approximately 27.47 million shares — equal to 14.88% of outstanding shares — as of September 30, 2025.
A total of 319 institutional investors currently hold ALGM stock, with a combined institutional value of approximately $3.97 billion as of the most recent 13F filing period.
Frequently asked questions
ALGM ownershipAllegro MicroSystems, Inc. (ALGM) is primarily owned by institutional investors, who hold approximately 73.0% of shares. The largest shareholder is FMR LLC with a 14.88% stake. Company insiders hold 33.35%. Data sourced from SEC Form 13F as of September 30, 2025.