PDF Solutions, Inc. reports that Needham Investment Management L.L.C., Needham Asset Management, LLC and George A. Needham collectively beneficially own 2,022,700 shares of Common Stock, representing 5.1% of the class. The Schedule 13G discloses shared voting and dispositive power of 2,022,700 shares for each filer. The filing is signed by James W. Giangrasso and George A. Needham on 05/15/2026.
Positive
None.
Negative
None.
Insights
Large passive stake reported by Needham-related entities.
The filing lists 2,022,700 shares and 5.1% ownership for Needham Investment Management L.L.C., Needham Asset Management, LLC and George A. Needham as of the filing date. Ownership is shown as shared voting and dispositive power, indicating control is exercised jointly.
Future disclosures in filings may note changes; cash‑flow treatment and any underlying advisory client identities are not detailed in this excerpt.
Disclosure shows joint/indirect holdings via advisory relationships.
The Schedule 13G states the securities are "directly owned by advisory clients of Needham Investment Management L.L.C." and notes none of those clients individually exceed 5.1%. This frames the position as aggregated client holdings reported by the adviser.
Material voting or disposition changes would appear in future amendments or Forms 13D/4 if the position becomes active or exceeds reporting thresholds.
Key Figures
Shares beneficially owned:2,022,700 sharesPercent of class:5.1%CUSIP:693282105+1 more
4 metrics
Shares beneficially owned2,022,700 sharesAmount reported for each Needham filer
Percent of class5.1%Percent of common stock reported in the Schedule 13G
CUSIP693282105PDF Solutions common stock CUSIP as listed
Filing signature date05/15/2026Signatures by James W. Giangrasso and George A. Needham
Key Terms
Schedule 13G, shared dispositive power, beneficially own
3 terms
Schedule 13Gregulatory
"reports that Needham Investment Management L.L.C., Needham Asset Management, LLC and George A. Needham collectively"
A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.
shared dispositive powerfinancial
"Shared Dispositive Power 2,022,700.00 for each filer"
Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
PDF Solutions, Inc.
(Name of Issuer)
Common Stock, $0.00015 par value
(Title of Class of Securities)
693282105
(CUSIP Number)
03/31/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
693282105
1
Names of Reporting Persons
Needham Investment Management L.L.C.
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
2,022,700.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,022,700.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,022,700.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.1 %
12
Type of Reporting Person (See Instructions)
IA, OO
SCHEDULE 13G
CUSIP Number(s):
693282105
1
Names of Reporting Persons
Needham Asset Management, LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
2,022,700.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,022,700.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,022,700.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.1 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP Number(s):
693282105
1
Names of Reporting Persons
George A. Needham
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
2,022,700.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,022,700.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,022,700.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
5.1 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
PDF Solutions, Inc.
(b)
Address of issuer's principal executive offices:
2858 De La Cruz Blvd., Santa Clara, California 95050
Item 2.
(a)
Name of person filing:
Needham Investment Management L.L.C.
Needham Asset Management, LLC
George A. Needham
(b)
Address or principal business office or, if none, residence:
Needham Investment Management L.L.C.
250 Park Avenue, 10th Floor
New York, New York 10117-1099
United States of America
Needham Asset Management, LLC
c/o Needham Investment Management L.L.C.
250 Park Avenue, 10th Floor
New York, New York 10117-1099
United States of America
George A. Needham
c/o Needham Investment Management L.L.C.
250 Park Avenue, 10th Floor
New York, New York 10117-1099
United States of America
(c)
Citizenship:
Needham Investment Management L.L.C. - Delaware
Needham Asset Management, LLC - Delaware
George A. Needham - United States
(d)
Title of class of securities:
Common Stock, $0.00015 par value
(e)
CUSIP Number(s):
693282105
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
Needham Investment Management L.L.C. - 2,022,700
Needham Asset Management, LLC - 2,022,700
George A. Needham - 2,022,700
(b)
Percent of class:
Needham Investment Management L.L.C. - 5.1%
Needham Asset Management, LLC - 5.1%
George A. Needham - 5.1%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
Needham Investment Management L.L.C. - 0
Needham Asset Management, LLC - 0
George A. Needham - 0
(ii) Shared power to vote or to direct the vote:
Needham Investment Management L.L.C. - 2,022,700
Needham Asset Management, LLC - 2,022,700
George A. Needham - 2,022,700
(iii) Sole power to dispose or to direct the disposition of:
Needham Investment Management L.L.C. - 0
Needham Asset Management, LLC - 0
George A. Needham - 0
(iv) Shared power to dispose or to direct the disposition of:
Needham Investment Management L.L.C. - 2,022,700
Needham Asset Management, LLC - 2,022,700
George A. Needham - 2,022,700
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
All of the securities reported in this Schedule 13G are directly owned by advisory clients of Needham Investment Management L.L.C. None of those advisory clients may be deemed to beneficially own more than 5% of the Common Stock, $0.00015 par value.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
Please see Exhibit B attached hereto.
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
Needham Investment Management L.L.C.
Signature:
/s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Chief Financial Officer
Date:
05/15/2026
Needham Asset Management, LLC
Signature:
/s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Authorized Person
Date:
05/15/2026
George A. Needham
Signature:
/s/ George A. Needham
Name/Title:
George A. Needham
Date:
05/15/2026
Exhibit Information
Exhibit A - Joint Filing Agreement
Exhibit B - Control Person Identification
