32% buyers of institutions opening or closing positions this quarter
21 more exits than new buyers, ownership fell 64.10 percentage points vs the prior quarter, and 3 well-known fund managers in the top 25.
32% buyers of institutions opening or closing positions this quarter
30.3% institutional ownership
NASPERS LTD portfolio allocation
Institutional ownership vs Internet Content & Information peers
4 Form 4 filings β executives buying or selling their own stock
Latest positioning in SMWB across 13F flow, ownership shift, marquee holders, and holder-count growth.
Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in SMWB held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | NASPERS LTD | 11.2M | $29.2M | 0.0% | 12.848% | 11.53% |
| 2 | MENORA MIVTACHIM HOLDINGS LTD. | 4.0M | $10.5M | 0.0% | 4.617% | 0.05% |
| 3 | Y.D. More Investments Ltd | 1.2M | $8.3M | -1.7% | 1.324% | 0.33% |
| 4 | Ulysses Management LLC | 3.0M | $7.8M | 0.0% | 3.448% | 0.98% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP | 3.0M | $7.7M | -1.2% | 3.411% | 0.00% |
| 6 | S Squared Technology, LLC | 1.6M | $4.2M | +106.4% | 1.840% | 1.58% |
| 7 | CenterBook Partners LP | 1.3M | $3.5M | +37.9% | 1.524% | 0.19% |
| 8 | Alpha Family Trust | 659K | $2.3M | 0.0% | 0.758% | 1.10% |
| 9 | MILLENNIUM MANAGEMENT LLC | 826K | $2.2M | +130.8% | 0.950% | 0.00% |
| 10 | MIRABELLA FINANCIAL SERVICES LLP | 793K | $2.1M | β | 0.911% | 0.20% |
| 11 | RENAISSANCE TECHNOLOGIES LLC | 740K | $1.9M | +104.6% | 0.851% | 0.00% |
| 12 | Herald Investment Management Ltd | 645K | $1.7M | 0.0% | 0.742% | 0.23% |
| 13 | CDC Financial, Inc. | 639K | $1.7M | +350.9% | 0.735% | 1.06% |
| 14 | MARSHALL WACE, LLP | 638K | $1.7M | +118.2% | 0.734% | 0.00% |
| 15 | Sphera Management Technology Funds Ltd | 615K | $1.6M | +28.1% | 0.707% | 0.90% |
| 16 | CITADEL ADVISORS LLC | 600K | $1.6M | +23.5% | 0.690% | 0.00% |
| 17 | MORGAN STANLEY | 592K | $1.5M | +130.6% | 0.681% | 0.00% |
| 18 | Connor, Clark & Lunn Investment Management Ltd. | 534K | $1.4M | -33.2% | 0.614% | 0.00% |
| 19 | P.A.W. CAPITAL CORP | 500K | $1.3M | +108.3% | 0.575% | 3.55% |
| 20 | Qube Research & Technologies Ltd | 416K | $1.1M | +2409.6% | 0.479% | 0.00% |
| 21 | NANO CAP NEW MILLENNIUM GROWTH FUND L P | 390K | $1.0M | +132.8% | 0.449% | 0.95% |
| 22 | Penn Capital Management Company, LLC | 360K | $941K | -77.3% | 0.414% | 0.07% |
| 23 | ARK Investment Management LLC | 352K | $919K | +48.9% | 0.405% | 0.01% |
| 24 | Schonfeld Strategic Advisors LLC | 289K | $755K | β | 0.332% | 0.01% |
| 25 | JANE STREET GROUP, LLC | 231K | $604K | -27.7% | 0.266% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in SMWB β a direct measure of their conviction.
Filings activity in SMWB during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 75 | 22% | 30.32% | 64.10 pp | $105M | 68% |
| Q4 2025 | 96 | +6.7% | 94.42% | 13.22 pp | $327M | 12% |
| Q3 2025 | 90 | 17% | 107.64% | +17.54 pp | $373M | +19% |
| Q2 2025 | 108 | +0.9% | 90.10% | 4.37 pp | $312M | 4.6% |
| Q1 2025 | 107 | 4.5% | 94.47% | 105.52 pp | $327M | 90% |
| Q4 2024 | 112 | +20% | 199.99% | +121.18 pp | $3.26B | +1096% |
| Q3 2024 | 93 | +24% | 78.81% | +16.71 pp | $273M | +27% |
| Q2 2024 | 75 | β | 62.10% | β | $215M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Latest Form 4 transactions by company officers and directors. Insider buys are widely viewed as the highest-conviction signal because executives are risking personal capital.
| Date | Insider | Action | Shares | Price | Value |
|---|---|---|---|---|---|
| Jun 1, 2026 | Offer Or | Buy | 50K | $4.15 | $208K |
| May 21, 2026 | Eilam Barak | Buy | 50K | $3.86 | $193K |
| May 18, 2026 | Rapaport-Dagim Tamar | Buy | 40K | $3.22 | $129K |
| May 18, 2026 | Offer Or | Buy | 3K | $3.20 | $10K |
Quick answers to the most common questions about buying SMWB stock.
Based on Q1 2026 13F filings, institutional ownership of Similarweb Ltd. stands at 30.3%, held across 75 reporting institutions.
NASPERS LTD is the largest reported institutional holder of SMWB, with approximately 11,173,265 shares worth $0.03B as of Q1 2026.
Yes β 3 widely-followed marquee investors appear among the top 25 institutional holders of SMWB, including RENAISSANCE TECHNOLOGIES LLC, CITADEL ADVISORS LLC, ARK Investment Management LLC.
Our composite Smart Money Score for SMWB is 44 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
19 institutions opened new positions in SMWB during Q1 2026, while 40 fully exited. 7 added to existing positions and 48 trimmed.
SMWB institutional ownership fell by 64.10 percentage points quarter-over-quarter, with a net change of β holders.
The top 10 institutions account for 74.0% of all reported 13F value in SMWB, and the top 25 account for 92.8%.
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.