PDF Solutions Inc. (PDFS) received an amended Schedule 13G from Needham entities reporting passive ownership of its common stock. As of December 31, 2025, Needham Investment Management L.L.C. and Needham Asset Management, LLC each report beneficial ownership of 1,965,000 shares, or 4.9% of the common stock.
These shares are held across advisory clients, primarily the Needham Aggressive Growth Fund with 1,465,000 shares (about 3.7% of the class), the Needham Growth Fund with 270,000 shares, and the Needham Small Cap Growth Fund with 230,000 shares. George A. Needham is also listed with shared voting and dispositive power over 1,965,000 shares, or 4.9%.
The filing states the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of PDF Solutions. Each reporting person disclaims beneficial ownership beyond their pecuniary interest.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
PDF SOLUTIONS INC
(Name of Issuer)
Common Stock, $0.00015 par value
(Title of Class of Securities)
693282105
(CUSIP Number)
12/31/2025
(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)
SCHEDULE 13G
CUSIP No.
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
1,965,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,965,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,965,000.00
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)
4.9 %
12
Type of Reporting Person (See Instructions)
IA, OO
SCHEDULE 13G
CUSIP No.
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
1,965,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,965,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,965,000.00
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)
4.9 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP No.
693282105
1
Names of Reporting Persons
NEEDHAM AGGRESSIVE GROWTH FUND
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
1,465,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,465,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,465,000.00
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)
3.7 %
12
Type of Reporting Person (See Instructions)
IV, OO
SCHEDULE 13G
CUSIP No.
693282105
1
Names of Reporting Persons
NEEDHAM GROWTH FUND
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
MARYLAND
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
270,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
270,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
270,000.00
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)
0.7 %
12
Type of Reporting Person (See Instructions)
IV, OO
SCHEDULE 13G
CUSIP No.
693282105
1
Names of Reporting Persons
NEEDHAM SMALL CAP GROWTH FUND
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
MARYLAND
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
230,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
230,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
230,000.00
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)
0.6 %
12
Type of Reporting Person (See Instructions)
IV, OO
SCHEDULE 13G
CUSIP No.
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
1,965,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,965,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,965,000.00
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)
4.9 %
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 Boulevard, Santa Clara, California 95050
Item 2.
(a)
Name of person filing:
Needham Investment Management L.L.C.
Needham Asset Management, LLC
Needham Aggressive Growth Fund
Needham Growth Fund
Needham Small Cap Growth Fund
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
Needham Aggressive Growth Fund
c/o Needham Investment Management L.L.C.
250 Park Avenue, 10th Floor
New York, New York 10117-1099
United States of America
Needham Growth Fund
c/o Needham Investment Management L.L.C.
250 Park Avenue, 10th Floor
New York, New York 10117-1099
United States of America
Needham Small Cap Growth Fund
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
Needham Aggressive Growth Fund - Delaware
Needham Growth Fund - Maryland
Needham Small Cap Growth Fund - Maryland
George A. Needham - United States
(d)
Title of class of securities:
Common Stock, $0.00015 par value
(e)
CUSIP No.:
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. - 1,965,000
Needham Asset Management, LLC - 1,965,000
Needham Aggressive Growth Fund - 1,465,000
Needham Growth Fund - 270,000
Needham Small Cap Growth Fund - 230,000
George A. Needham - 1,965,000
(b)
Percent of class:
Needham Investment Management L.L.C. - 4.9%
Needham Asset Management, LLC - 4.9%
Needham Aggressive Growth Fund - 3.7%
Needham Growth Fund - 0.7%
Needham Small Cap Growth Fund - 0.6%
George A. Needham - 4.9%
(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
Needham Aggressive Growth Fund - 0
Needham Growth Fund - 0
Needham Small Cap Growth Fund - 0
Needham Contrarian (QP) Fund, LP - 0
Needham Emerging Growth Partners, LP - 0
George A. Needham - 0
(ii) Shared power to vote or to direct the vote:
Needham Investment Management L.L.C. - 1,965,000
Needham Asset Management, LLC - 1,965,000
Needham Aggressive Growth Fund - 1,465,000
Needham Growth Fund - 270,000
Needham Small Cap Growth Fund - 230,000
George A. Needham - 1,965,000
(iii) Sole power to dispose or to direct the disposition of:
Needham Investment Management L.L.C. - 0
Needham Asset Management, LLC - 0
Needham Aggressive Growth Fund - 0
Needham Growth Fund - 0
Needham Small Cap Growth Fund - 0
Needham Contrarian (QP) Fund, LP - 0
Needham Emerging Growth Partners, LP - 0
George A. Needham - 0
(iv) Shared power to dispose or to direct the disposition of:
Needham Investment Management L.L.C. - 1,965,000
Needham Asset Management, LLC - 1,965,000
Needham Aggressive Growth Fund - 1,465,000
Needham Growth Fund - 270,000
Needham Small Cap Growth Fund - 230,000
George A. Needham - 1,965,000
Item 5.
Ownership of 5 Percent or Less of a Class.
Ownership of 5 percent or less of a class
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:
By: /s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Chief Financial Officer
Date:
02/13/2026
NEEDHAM ASSET MANAGEMENT, LLC
Signature:
By: /s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Authorized Person
Date:
02/13/2026
NEEDHAM AGGRESSIVE GROWTH FUND
Signature:
By: /s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Chief Financial Officer
Date:
02/13/2026
NEEDHAM GROWTH FUND
Signature:
By: /s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Chief Financial Officer
Date:
02/13/2026
NEEDHAM SMALL CAP GROWTH FUND
Signature:
By: /s/ James W. Giangrasso
Name/Title:
James W. Giangrasso, Chief Financial Officer
Date:
02/13/2026
GEORGE A. NEEDHAM
Signature:
By: /s/ George A. Needham
Name/Title:
George A. Needham
Date:
02/13/2026
Comments accompanying signature: * Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of his, her or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
To the extent that "ownership of 5 percent or less of a class" was indicated in Item 5, such response only applies to the Reporting Person(s) that indicated elsewhere herein that it beneficially owns five percent (5%) or less of the class.
Exhibit Information
Exhibit A - Joint Filing Agreement
Exhibit B - Control Person Identification
What ownership in PDF Solutions Inc. (PDFS) do the Needham entities report?
Needham Investment Management L.L.C. and Needham Asset Management, LLC each report beneficial ownership of 1,965,000 shares of PDF Solutions common stock, representing 4.9% of the class. These shares are held across various advisory client accounts managed by the Needham entities.
How many PDF Solutions (PDFS) shares are held by Needham Aggressive Growth Fund?
Needham Aggressive Growth Fund reports beneficial ownership of 1,465,000 shares of PDF Solutions common stock, representing approximately 3.7% of the outstanding class. Voting and dispositive powers over these shares are reported as shared rather than sole for the fund and related entities.
Does any Needham fund individually own 5% or more of PDF Solutions (PDFS)?
No individual Needham fund is reported as owning at least 5% of PDF Solutions’ common stock. The filing states all securities are directly owned by advisory clients of Needham Investment Management L.L.C., and none of those advisory clients may be deemed to beneficially own more than 5% of the class.
What is George A. Needham’s reported beneficial ownership in PDF Solutions (PDFS)?
George A. Needham is reported as having shared voting and dispositive power over 1,965,000 shares of PDF Solutions common stock, equal to about 4.9% of the class. The filing notes a disclaimer of beneficial ownership beyond his pecuniary interest in those securities.
Is the Needham position in PDF Solutions (PDFS) reported as passive or for control?
The position is reported as passive. The certification states the securities were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose or effect of changing or influencing control of PDF Solutions Inc.
How is voting and dispositive power over PDF Solutions (PDFS) shares allocated among Needham entities?
The filing shows no sole voting or dispositive power for the Needham entities or funds. Instead, they report shared voting and shared dispositive power over the PDF Solutions shares held by advisory clients, totaling up to 1,965,000 shares for certain reporting persons.
