[8-K] CALIX, INC Reports Material Event

Rhea-AI Filing Summary

Calix, Inc. filed a current report noting it has released a press release and a detailed stockholder letter presenting its financial results for the fourth quarter ended December 31, 2025. Both documents are attached as exhibits.

The stockholder letter highlights several non-GAAP metrics, including non-GAAP gross margin, operating expenses, functional investment categories, effective income tax rate, net income, net income per diluted share and free cash flow. Calix explains these measures exclude non-cash stock-based compensation, intangible asset amortization and certain income tax effects, and are used by management to evaluate performance and set operational goals. Reconciliations to the most comparable U.S. GAAP figures are provided in tabular form in the stockholder letter.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

 CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 28, 2026

CALIX, INC.

(Exact name of Registrant as specified in its charter)

Delaware

001-34674

68-0438710

(State or other jurisdiction of incorporation)

(Commission File No.)

(I.R.S. Employer Identification No.)

3155 Olsen Drive, Suite 450, San Jose, California

95117

(Address of principal executive offices)

(Zip Code)

(408) 514-3000

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class

Trading Symbol

Name of Each Exchange on Which Registered

Common Stock, par value $0.025 per share

CALX

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging Growth Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act).  o

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Item 2.02     Results of Operations and Financial Condition.

On January 28, 2026, Calix, Inc. (the “Company”) issued a press release announcing it has publicly disseminated a stockholder letter with its financial results for the fourth quarter ended December 31, 2025. The press release is attached hereto as Exhibit 99.1. The stockholder letter, a copy of which is attached hereto as Exhibit 99.2 and incorporated herein by reference, includes reference to the non-GAAP measures of non-GAAP gross margin, non-GAAP operating expenses, non-GAAP sales and marketing investments, non-GAAP research and development investments, non-GAAP general and administrative investments, non-GAAP effective income tax rate, non-GAAP net income or profitability, non-GAAP net income per diluted common share and non-GAAP free cash flow. These non-GAAP measures are provided to enhance the reader’s understanding of the Company’s operating performance as they exclude non-cash stock-based compensation and intangible asset amortization and the impact from changes in income taxes, which the Company believes are not indicative of its core operating results. Management believes that the non-GAAP measures used in this stockholder letter provide investors with important perspectives into the Company’s ongoing business performance and management uses these non-GAAP measures to evaluate financial results and to establish operational goals. The presentation of these non-GAAP measures is not meant to be a substitute for results presented in accordance with U.S. GAAP, but rather should be evaluated in conjunction with those GAAP results. A reconciliation of the non-GAAP results to the most directly comparable U.S. GAAP results is contained in tabular form in Exhibit 99.2. The non-GAAP financial measures used by the Company may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies.

Such information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and is not incorporated by reference into any filing of the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

Item 9.01     Financial Statements and Exhibits.

(d) Exhibits 

Exhibit No.						Description
99.1						Press Release, dated January 28, 2026 announcing fourth quarter 2025 financial results.
99.2						Stockholder Letter dated January 28, 2026 announcing financial results of the Company.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date:

January 28, 2026

CALIX, INC.

By:

/s/ Cory Sindelar

Cory Sindelar

Chief Financial Officer

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EXHIBIT INDEX

Exhibit No.						Description
99.1						Press Release, dated January 28, 2026 announcing fourth quarter 2025 financial results.
99.2						Stockholder Letter dated January 28, 2026 announcing financial results of the Company.

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FAQ

What did Calix (CALX) disclose in this 8-K filing?

Calix disclosed that it issued a press release and a stockholder letter presenting financial results for the fourth quarter ended December 31, 2025. These materials are included as Exhibits 99.1 and 99.2 and form the core of the company’s results communication.

Which non-GAAP financial measures does Calix (CALX) emphasize?

Calix emphasizes non-GAAP gross margin, operating expenses, functional investment measures, effective income tax rate, net income, diluted non-GAAP EPS and free cash flow. The company says these exclude stock-based compensation, intangible amortization and certain tax impacts to better reflect its core operating performance.

How does Calix (CALX) support its non-GAAP metrics for investors?

Calix provides reconciliations from its non-GAAP metrics to the most directly comparable U.S. GAAP results in tabular form within the stockholder letter attached as Exhibit 99.2. Management states it also uses these metrics internally for evaluating financial results and setting operational goals.

Are Calix’s (CALX) non-GAAP metrics comparable to those of other companies?

Calix notes its non-GAAP financial measures may be calculated differently from similarly titled metrics used by other companies. As a result, direct comparisons can be difficult, and investors need to rely on the specific definitions and reconciliations provided in the company’s stockholder letter.

Does Calix (CALX) treat the fourth-quarter results information as filed or furnished?

Calix states that the information in the press release and stockholder letter related to its fourth-quarter 2025 results is furnished, not filed, under the Securities Exchange Act. This means it is not subject to certain liability provisions associated with filed information.