PDF Solutions Inc
Ownership
Ownership Structure
Who owns PDF Solutions Inc (PDFS)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 81.7% of the shares are freely tradable; institutional investors hold 83.9%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 11.52 | 4,866,177 | -0.4 | 03/31/2026 |
| Needham Investment Management, LLC | 4.79 | 2,022,700 | +2.9 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 3.32 | 1,400,722 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 3.29 | 1,388,122 | +0.0 | 03/31/2026 |
| Wasatch Advisors LP | 3.27 | 1,380,739 | +171.9 | 06/30/2026 |
| Barrow Hanley Mewhinney & Strauss LLC | 3.13 | 1,319,627 | +15.7 | 06/30/2026 |
| State Street Corp | 2.82 | 1,192,408 | +3.5 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 5.44 | 2,298,076 | +0.0 | 08/31/2026 |
| Needham Aggressive Growth Retail | 4.04 | 1,705,000 | +7.4 | 06/30/2026 |
| Vanguard MStar Total Stk Mkt Idx Invest | 2.84 | 1,198,459 | +0.4 | 07/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Strojwas Andrzej | Chief Technology Officer | 90,965 | 3,975,171 $ | Aug 31, 2026 | direct |
| Zhang Shuo | Director | 23,380 | 1,021,706 $ | Aug 12, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 31, 2026 | Strojwas Andrzej | Chief Technology Officer | Sell | 3,394 | 44.41 | 150,728 |
| Aug 12, 2026 | Zhang Shuo | Director | Sell | 1,501 | 51.47 | 77,256 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.