Alector, Inc.
Alector, Inc. (ALEC) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ALEC · as of Sep 30, 2025
Ownership Breakdown
157
Institutional Holders
▲ 20 vs Q2
$221.31M
Total Inst. Value
▲ $122.59M vs Q2
111.03M
Shares Outstanding
freeFloat 70.68%
74.77M
13F Shares Held
▲ 4.26M 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
ALEC largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
FMR LLC biological products, (no diagnostic substances) | 15.18M | 15.13% | 15.13% | $44.94B | Nov 13, 2025 | ▲ 183.0K |
BLACKROCK, INC. biological products, (no diagnostic substances) | 7.20M | 7.17% | 7.17% | $21.31B | Nov 12, 2025 | ▼ 775.6K |
RTW INVESTMENTS, LP biological products, (no diagnostic substances) | 6.99M | 6.96% | 6.96% | $20.69B | Nov 14, 2025 | NEW |
VANGUARD GROUP INC biological products, (no diagnostic substances) | 6.03M | 6.01% | 6.01% | $17.86B | Nov 7, 2025 | ▲ 47.0K |
MERCK & CO., INC. biological products, (no diagnostic substances) | 3.55M | 3.53% | 3.53% | $10.50B | Nov 12, 2025 | — held |
ACADIAN ASSET MANAGEMENT LLC biological products, (no diagnostic substances) | 2.37M | 2.36% | 2.36% | $7.02B | Nov 13, 2025 | ▲ 202.6K |
PRICE T ROWE ASSOCIATES INC /MD/ biological products, (no diagnostic substances) | 2.19M | 2.18% | 2.18% | $6.47B | Nov 14, 2025 | ▼ 2.69M |
GEODE CAPITAL MANAGEMENT, LLC biological products, (no diagnostic substances) | 1.86M | 1.85% | 1.85% | $5.51B | Nov 12, 2025 | ▼ 120.8K |
STATE STREET CORP biological products, (no diagnostic substances) | 1.73M | 1.73% | 1.73% | $5.13B | Nov 14, 2025 | ▲ 24.8K |
EVERSEPT PARTNERS, LP biological products, (no diagnostic substances) | 1.49M | 1.48% | 1.48% | $4.41B | Nov 14, 2025 | ▼ 497.3K |
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
25
Increased
+4.89M shares3
New Positions
first time holders16
Decreased
−5.72M shares0
Sold Out
fully exitedNet shares change (top 50)
829.8K
+4.89M / −5.72M
Net new holders
+12
3 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
ALEC 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.
0
Buy transactions
1
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 |
|---|---|---|---|---|---|---|---|
SCHELLER RICHARD H director | Jun 1, 2026 | Award | 10,833 | — | — | 106.2K | Form 4 ↗ |
Wong-Sarad Grace Principal Accounting Officer | Apr 16, 2026 | Sale | 1,820 | $2.65 | $4.8K | 104.6K | Form 4 ↗ |
Rosenthal Arnon Chief Executive Officer | Mar 13, 2026 | Award | 116,246 | — | — | 2.45M | Form 4 ↗ |
Berkley Neil Lindsay CFO & Chief Business Officer | Mar 15, 2026 | Award | 54,600 | — | — | 399.3K | Form 4 ↗ |
Wong-Sarad Grace Principal Accounting Officer | Mar 10, 2026 | Sale | 1,000 | $2.65 | $2.6K | 106.5K | Form 4 ↗ |
Wong-Sarad Grace Principal Accounting Officer | Mar 3, 2026 | Sale | 3,367 | $2.08 | $7.0K | 107.5K | Form 4 ↗ |
Wong-Sarad Grace Principal Accounting Officer | Mar 2, 2026 | Sale | 8,071 | $2.12 | $17.1K | 110.8K | Form 4 ↗ |
Rosenthal Arnon Chief Executive Officer | Mar 2, 2026 | Sale | 81,864 | $2.12 | $173.8K | 2.34M | Form 4 ↗ |
Berkley Neil Lindsay CFO & Chief Business Officer | Mar 2, 2026 | Sale | 29,649 | $2.12 | $63.0K | 344.7K | Form 4 ↗ |
Wong-Sarad Grace Principal Accounting Officer | Feb 26, 2026 | Sale | 4,079 | $2.50 | $10.2K | 118.9K | 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
Alector, Inc. (ALEC) is primarily owned by institutional investors, who hold approximately 67.3% of total shares outstanding. Company insiders own approximately 29.32%, while retail and public investors account for the remaining 3.34%.
The largest institutional shareholder of Alector, Inc. is FMR LLC, holding approximately 15.18 million shares — equal to 15.13% of outstanding shares — as of September 30, 2025.
A total of 157 institutional investors currently hold ALEC stock, with a combined institutional value of approximately $221,307,345 as of the most recent 13F filing period.
Frequently asked questions
ALEC ownershipAlector, Inc. (ALEC) is primarily owned by institutional investors, who hold approximately 67.3% of shares. The largest shareholder is FMR LLC with a 15.13% stake. Company insiders hold 29.32%. Data sourced from SEC Form 13F as of September 30, 2025.