PDF Solutions Inc. (NASDAQ: PDFS), a provider of semiconductor process control and data analytics solutions, disclosed on July 2, 2026 that director Shuo Zhang received an award of 2,689 restricted stock units under the company's Director Compensation Program, effective July 1, 2026. The grant brings Zhang's total beneficial ownership of PDF Solutions common stock to 24,881 shares following the transaction. The RSUs are structured to vest in four equal quarterly installments of 25% each, subject to Zhang's continued service on the board. Investors tracking insider ownership levels and board compensation practices at the Santa Clara-based company may find the disclosure relevant as part of their broader governance monitoring.

Key Points

  • Director Shuo Zhang was awarded 2,689 restricted stock units on July 1, 2026 under the PDF Solutions Director Compensation Program
  • Zhang's total beneficial ownership following the transaction stands at 24,881 shares of common stock, held directly
  • RSUs vest in four equal installments of 25% each on the first day of every calendar quarter following the grant effective date, contingent on continued service
  • The Form 4 was filed on July 2, 2026 and signed by Adnan Raza as Attorney-In-Fact for Shuo Zhang
  • Investors should watch for subsequent Form 4 filings disclosing vesting events as quarterly installments are delivered

Shuo Zhang's RSU Award Under the PDF Solutions Director Compensation Program

The Form 4 statement of changes in beneficial ownership, filed with the U.S. Securities and Exchange Commission on July 2, 2026, confirms that Shuo Zhang — a director of PDF Solutions Inc. — received a grant of 2,689 restricted stock units on July 1, 2026. The award was made pursuant to the company's Director Compensation Program, a standing equity incentive arrangement that PDF Solutions uses to compensate members of its board of directors. The transaction is recorded in Table I of the filing as an acquisition of non-derivative securities, carrying a transaction code of "A," signifying an award rather than an open-market purchase.

The filing notes that the shares underlying the RSU award are classified as common stock of PDF Solutions Inc. The grant price or fair market value of the shares at the time of the award was not separately itemized in the filing; the company did not disclose this figure in the filing beyond the transaction itself. Following the reported transaction, Zhang's direct beneficial ownership of PDF Solutions common stock stands at 24,881 shares, all held in a direct ownership capacity with no indirect beneficial ownership reported at this time.

Quarterly Vesting Schedule and Continued Service Requirement

According to the explanation of responses provided in the Form 4, the 2,689 RSUs will vest in four equal installments, each representing 25% of the total award. Vesting occurs on the first day of each calendar quarter following the grant effective date of July 1, 2026. This means investors should anticipate the first vesting event to occur on October 1, 2026, with subsequent installments following on January 1, April 1, and July 1 of the years thereafter, assuming Zhang fulfills the conditions attached to each vesting date.

A key condition of the vesting schedule is the recipient's continued service through each applicable vesting date. Should Zhang's service as a director of PDF Solutions cease prior to any scheduled vesting date, unvested RSUs could be forfeited in accordance with the terms of the Director Compensation Program. The filing does not specify the precise forfeiture provisions or acceleration clauses, if any, that might apply in the event of a change of control or other corporate event. Investors seeking the full terms of the Director Compensation Program would need to consult PDF Solutions' most recent proxy statement or equity compensation plan documents filed with the SEC.

How This Grant Fits Into PDF Solutions' Board Equity Compensation Structure

Equity-based compensation for independent directors is a standard practice among NASDAQ-listed technology and semiconductor companies. For PDF Solutions, granting RSUs under a Director Compensation Program aligns board members' financial interests with those of shareholders, as the value of unvested and vested shares fluctuates with the company's stock price. The use of quarterly vesting milestones, rather than annual cliff vesting, provides a more gradual alignment mechanism and reduces the risk of a large simultaneous disposal of shares at a single vesting date.

The specific size of the grant — 2,689 RSUs — reflects the current award level set by the PDF Solutions board under its compensation program, though the filing does not detail whether this represents a standard annual grant, a pro-rated award, or a grant tied to a specific board committee appointment. Investors interested in understanding the full context of director compensation at PDF Solutions are encouraged to review the company's most recent definitive proxy statement (DEF 14A), which typically outlines total director pay, equity grant policies, and the rationale behind grant sizing decisions.

Zhang's Total Beneficial Ownership Position at PDF Solutions

Prior to the July 1, 2026 RSU grant, Zhang's directly held position in PDF Solutions common stock would have stood at 22,192 shares — calculated by subtracting the 2,689 newly awarded RSUs from the post-transaction total of 24,881 shares. After the grant is recorded, the 24,881-share position represents Zhang's confirmed direct beneficial ownership as of the most recent transaction. It is important to note that the RSUs themselves, while granted, have not yet converted to freely tradable shares, as they remain subject to the quarterly vesting schedule described in the filing.

The Form 4 does not report any holdings through trusts, family members, or other indirect ownership structures for Zhang at this time. All 24,881 shares are reported as directly owned. Investors monitoring insider ownership trends at PDF Solutions should be aware that the 24,881 figure includes both previously vested shares and any prior equity awards that have already converted to common stock, in addition to the newly granted RSUs that remain unvested as of the filing date.

Procedural Details of the Form 4 Filing and Attorney-In-Fact Signature

The Form 4 was filed on July 2, 2026 — one day after the transaction date of July 1, 2026 — consistent with the SEC's requirement that insiders report changes in beneficial ownership within two business days of a reportable transaction. The filing was signed by Adnan Raza, identified as Attorney-In-Fact for Shuo Zhang, indicating that Zhang has granted a legal power of attorney to Raza to execute and file Section 16 reporting documents on his behalf. This arrangement is common among corporate directors and officers who wish to ensure timely regulatory compliance.

The filing is submitted as an individual Form 4, rather than a joint filing by multiple reporting persons, as indicated by the checked box confirming it is a "Form filed by One Reporting Person." No amendment date is listed, confirming this is an original filing and not a correction to a previously submitted document. The OMB approval number cited — 3235-0287 — is the standard identifier for Form 4 filings, and the estimated average burden for completing such a form is noted as 0.5 hours per response.

Section 16 Reporting Obligations and Regulatory Context for PDFS Insiders

As a director of a NASDAQ-listed company, Shuo Zhang is classified as a reporting person under Section 16(a) of the Securities Exchange Act of 1934. This provision requires officers, directors, and shareholders owning more than 10% of a registered equity class to publicly disclose their ownership and any changes thereto. The Form 4 is the primary vehicle for reporting transactions that change an insider's beneficial ownership, and timely filing is a monitored compliance obligation enforced by the SEC.

The filing does not indicate that Zhang is a 10% or greater beneficial owner of PDF Solutions, nor that he is filing in any capacity other than as a director. The box on the form relating to transactions made pursuant to a Rule 10b5-1(c) plan — which provides an affirmative defense against insider trading allegations for pre-scheduled trading programs — is not checked, which is consistent with an RSU grant made by the company to a director rather than a discretionary purchase or sale initiated by the insider. No derivative securities transactions are reported in Table II of the Form 4.

PDF Solutions' Semiconductor Analytics Business and Investor Backdrop

PDF Solutions Inc. operates in the semiconductor yield improvement and process control analytics sector, providing software and services that help chipmakers optimize manufacturing efficiency and data utilization. The company's PDFS ticker trades on the NASDAQ exchange and serves customers across the global semiconductor supply chain. Insider equity activity at PDF Solutions, including director RSU grants such as this one, is regularly monitored by institutional and retail investors as one data point in evaluating long-term executive and board confidence in the company's trajectory.

While a routine RSU grant under a director compensation program does not in itself carry the same signal weight as an open-market purchase or a large discretionary sale, it does contribute to the overall picture of board-level ownership alignment. Over time, as quarterly vesting installments convert to freely tradable shares, investors may watch whether Zhang retains the vested shares or elects to dispose of them — transactions that would in turn require their own Form 4 disclosures. The immediate share price impact of this filing was not clear from available public information.

What Investors Should Monitor in Upcoming PDFS Insider Disclosures

The four-installment vesting structure of this RSU grant means that PDF Solutions shareholders should anticipate a series of follow-on Form 4 filings from Zhang beginning in October 2026, when the first 25% tranche — approximately 672 shares — is expected to vest. Each vesting event will constitute a reportable change in beneficial ownership and will trigger a new Form 4 filing obligation within two business days. Investors tracking the evolution of insider ownership at PDF Solutions can monitor these filings through the SEC's EDGAR database.

Beyond the individual grant to Zhang, investors following PDFS may also wish to watch for similar RSU awards to other board members under the same Director Compensation Program, which may be filed in close proximity to this disclosure given that equity grants to directors are often made on the same schedule. Any changes to the Director Compensation Program itself — such as adjustments to grant size, vesting schedules, or eligibility criteria — would typically be disclosed in PDF Solutions' annual proxy statement. No additional guidance, financial results, or operational updates were contained within or associated with this Form 4 filing.