Ranked by reported Q2 2026 13F market value
Share of total reported institutional value in ALEC held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | TCG Crossover Management, LLC | 10.0M | $20.1M | 0.0% | 9.007% | 0.48% |
| 2 | BlackRock, Inc. | 7.8M | $15.8M | +1.4% | 7.069% | 0.00% |
| 3 | Nantahala Capital Management, LLC | 4.3M | $8.7M | +53.3% | 3.889% | 0.14% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 4.0M | $8.1M | +9.0% | 3.611% | 0.00% |
| 5 | Kynam Capital Management, LP | 3.8M | $7.7M | +90.4% | 3.430% | 0.42% |
| 6 | BALYASNY ASSET MANAGEMENT L.P. | 3.8M | $7.5M | +27.8% | 3.379% | 0.01% |
| 7 | Merck & Co., Inc. | 3.5M | $7.1M | 0.0% | 3.194% | 1.35% |
| 8 | 683 Capital Management, LLC | 3.2M | $6.4M | 0.0% | 2.882% | 0.32% |
| 9 | D. E. Shaw & Co., Inc. | 3.0M | $5.9M | -11.2% | 2.666% | 0.00% |
| 10 | ADAR1 Capital Management, LLC | 2.9M | $5.8M | +174.6% | 2.597% | 0.27% |
| 11 | VANGUARD PORTFOLIO MANAGEMENT LLC | 2.8M | $5.7M | +9.2% | 2.540% | 0.00% |
| 12 | GEODE CAPITAL MANAGEMENT, LLC | 2.5M | $4.9M | +7.3% | 2.211% | 0.00% |
| 13 | Spruce Street Capital LP | 2.1M | $4.2M | 0.0% | 1.892% | 0.83% |
| 14 | MILLENNIUM MANAGEMENT LLC | 2.0M | $4.0M | +0.5% | 1.791% | 0.00% |
| 15 | Ikarian Capital, LLC | 2.0M | $4.0M | -4.8% | 1.786% | 0.43% |
| 16 | STATE STREET CORP | 1.9M | $3.8M | +0.8% | 1.693% | 0.00% |
| 17 | JACOBS LEVY EQUITY MANAGEMENT, INC | 1.8M | $3.5M | -18.0% | 1.591% | 0.01% |
| 18 | MEDICI CAPITAL LLC | 1.7M | $3.3M | 0.0% | 1.488% | 6.51% |
| 19 | Affinity Asset Advisors, LLC | 1.5M | $3.0M | +202.0% | 1.360% | 0.14% |
| 20 | Eversept Partners, LP | 1.4M | $2.9M | +5.4% | 1.282% | 0.15% |
| 21 | FMR LLC | 1.4M | $2.8M | -22.3% | 1.258% | 0.00% |
| 22 | AQR CAPITAL MANAGEMENT LLC | 1.3M | $2.6M | +84.1% | 1.179% | 0.00% |
| 23 | Euclidean Capital LLC | 1.3M | $2.6M | 0.0% | 1.178% | 0.60% |
| 24 | MACKENZIE FINANCIAL CORP | 1.1M | $2.2M | +29.4% | 1.000% | 0.00% |
| 25 | DEUTSCHE BANK AG\ | 1.1M | $2.2M | +0.5% | 0.989% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in ALEC — a direct measure of their conviction.
Filings activity in ALEC during Q2 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q2 2026 | 141 | +2.9% | 82.97% | +2.70 pp | $176M | 3.0% |
| Q1 2026 | 137 | +6.2% | 80.27% | +3.02 pp | $182M | +44% |
| Q4 2025 | 129 | 13% | 77.25% | +6.50 pp | $126M | 40% |
| Q3 2025 | 148 | +8.8% | 70.75% | +0.65 pp | $209M | +138% |
| Q2 2025 | 136 | 2.9% | 70.10% | 2.91 pp | $88M | +1.7% |
| Q1 2025 | 140 | 6.0% | 73.01% | 1.16 pp | $87M | 36% |
| Q4 2024 | 149 | 6.3% | 74.17% | 0.31 pp | $134M | 59% |
| Q3 2024 | 159 | — | 74.48% | — | $329M | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying ALEC stock.
Based on Q2 2026 13F filings, institutional ownership of Alector, Inc. stands at 83.0%, held across 141 reporting institutions.
TCG Crossover Management, LLC is the largest reported institutional holder of ALEC, with approximately 10,000,000 shares worth $0.02B as of Q2 2026.
Yes — 1 widely-followed marquee investor appear among the top 25 institutional holders of ALEC, including MILLENNIUM MANAGEMENT LLC.
Our composite Smart Money Score for ALEC is 63 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
13 institutions opened new positions in ALEC during Q2 2026, while 8 fully exited. 47 added to existing positions and 80 trimmed.
ALEC institutional ownership rose by 2.70 percentage points quarter-over-quarter, with a net change of +4 holders.
The top 10 institutions account for 52.9% of all reported 13F value in ALEC, and the top 25 account for 82.3%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Alector, Inc. (ALEC) Institutional Ownership