[425] SYNOVUS FINANCIAL CORP Business Combination Communication

Rhea-AI Filing Summary

Synovus Financial Corp. filed a Rule 425 communication regarding its proposed merger with Pinnacle Financial Partners. The filing reiterates that Steel Newco Inc. filed a Form S-4 to register Newco common stock to be issued to Synovus and Pinnacle shareholders, and that the registration statement was declared effective on September 30, 2025. A definitive joint proxy statement/prospectus was filed and mailing to shareholders commenced on or about September 30, 2025.

The communication contains extensive forward‑looking statements and outlines risks that could affect outcomes, including shareholder and governmental approvals, integration timing and costs, realization of synergies, potential dilution from Newco share issuance, and general market conditions. It also states this is not an offer to sell or a solicitation of an offer to buy securities and encourages investors to review the effective S‑4 and joint proxy/prospectus for details.

Insights

Bank M&A analyst

Process update: S-4 effective; proxies mailed; approvals pending.

This communication signals the merger process is advancing: the Newco S‑4 is effective as of September 30, 2025, and the definitive joint proxy/prospectus has been mailed to shareholders. That positions both banks to seek shareholder votes and satisfy regulatory steps.

Closing remains contingent on several factors disclosed here, including shareholder approvals, required governmental approvals, integration execution, and costs. The filing notes potential dilution due to issuance of Newco common stock to both shareholder bases.

Key milestones are the shareholder votes and regulatory determinations referenced in the materials. Actual impact depends on approvals and integration outcomes; the communication makes no financial guidance beyond standard forward‑looking statements.

Filed by Synovus Financial Corp.

pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-6

under the Securities Exchange Act of 1934

Subject Company: Steel Newco Inc.

Commission File No.: 333-289866

Date: October 30, 2025

[The following is a screenshot of a social media post that was posted by Kevin Blair, the Chairman, Chief Executive Officer and President of Synovus Financial Corp., on LinkedIn on October 30, 2025.]

Forward-Looking Statements

This communication contains statements that constitute “forward-looking statements” within the meaning of, and subject to the protections of, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical fact are forward-looking statements. These forward-looking statements include, but are not limited to, statements about the benefits of the proposed transaction between Synovus Financial Corp.  (“Synovus”) and Pinnacle Financial Partners, Inc. (“Pinnacle”), including future financial and operating results (including the anticipated impact of the proposed transaction on Synovus’ and Pinnacle’s respective earnings and tangible book value), statements related to the expected timing of the completion of the proposed transaction, the combined company’s plans, objectives, expectations and intentions, and other statements that are not historical facts.  You can identify these forward-looking statements through the use of words such as “believes,” “anticipates,” “expects,” “may,” “will,” “assumes,” “should,” “predicts,” “could,” “would,” “intends,” “targets,” “estimates,” “projects,” “plans,” “potential” and other similar words and expressions of the future or otherwise regarding the outlook for Synovus’, Pinnacle’s or combined company’s future businesses and financial performance and/or the performance of the banking industry and economy in general.

Prospective investors are cautioned that any such forward-looking statements are not guarantees of future performance and involve known and unknown risks and uncertainties which may cause the actual results, performance or achievements of Synovus, Pinnacle or the combined company to be materially different from the future results, performance or achievements expressed or implied by such forward-looking statements. Forward-looking statements are based on the information known to, and current beliefs and expectations of, Synovus or Pinnacle and are subject to significant risks and uncertainties. Actual results may differ materially from those contemplated by such forward-looking statements.  A number of factors could cause actual results to differ materially from those contemplated by the forward-looking statements in this communication. Many of these factors are beyond Synovus’, Pinnacle’s or the combined company’s ability to control or predict.  These factors include, among others, (1) the risk that the cost savings and synergies from the proposed transaction may not be fully realized or may take longer than anticipated to be realized, (2) disruption to Synovus’ business and to Pinnacle’s business as a result of the announcement and pendency of the proposed transaction, (3) the risk that the integration of Pinnacle’s and Synovus’ respective businesses and operations will be materially delayed or will be more costly or difficult than expected, including as a result of unexpected factors or events, (4) the failure to obtain the necessary approvals by the shareholders of Synovus or Pinnacle, (5) the amount of the costs, fees, expenses and charges related to the transaction, (6) the ability by each of Synovus and Pinnacle to obtain required governmental approvals of the proposed transaction on the timeline expected, or at all, and the risk that such approvals may result in the imposition of conditions that could adversely affect the combined company after the closing of the proposed transaction or adversely affect the expected benefits of the proposed transaction, (7) reputational risk and the reaction of each company’s customers, suppliers, employees or other business partners to the proposed transaction, (8) the failure of the closing conditions in the merger agreement to be satisfied, or any unexpected delay in closing the proposed transaction or the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement, (9) the dilution caused by the issuance of shares of the combined company’s common stock in the transaction, (10) the possibility that the proposed transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events, (11) risks related to management and oversight of the expanded business and operations of the combined company following the closing of the proposed transaction, (12) the possibility the combined company is subject to additional regulatory requirements as a result of the proposed transaction or expansion of the combined company’s business operations following the proposed transaction, (13) the outcome of any legal or regulatory proceedings or governmental inquiries or investigations that may be currently pending or later instituted against Synovus, Pinnacle or the combined company and (14) general competitive, economic, political and market conditions and other factors that may affect future results of Synovus and Pinnacle including changes in asset quality and credit risk; the inability to sustain revenue and earnings growth; changes in interest rates and capital markets; inflation; customer borrowing, repayment, investment and deposit practices; the impact, extent and timing of technological changes; and capital management activities.  Additional factors which could affect future results of Synovus and Pinnacle can be found in Synovus’ or Pinnacle’s filings with the Securities and Exchange Commission (the “SEC”), including in Synovus’ Annual Report on Form 10-K for the year ended December 31, 2024, under the captions “Forward-Looking Statements” and “Risk Factors,” and Synovus’ Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, and Pinnacle’s Annual Report on Form 10-K for the year ended December 31, 2024, under the captions “Forward-Looking Statements” and “Risk Factors,” and in Pinnacle’s Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. Undue reliance should not be placed on any forward-looking statements, which are based on current expectations and speak only as of the date that they are made. Synovus and Pinnacle do not assume any obligation to update any forward-looking statements as a result of new information, future developments or otherwise, except as otherwise may be required by law.

-2-

Important Information About the Merger and Where to Find It

Steel Newco Inc. (“Newco”) filed a registration statement on Form S-4 (File No. 333-289866) with the SEC on August 26, 2025, and an amendment on September 29, 2025, to register the shares of Newco common stock that will be issued to Pinnacle shareholders and Synovus shareholders in connection with the proposed transaction.  The registration statement includes a joint proxy statement of Synovus and Pinnacle that also constitutes a prospectus of Newco.  The registration statement was declared effective on September 30, 2025.  Newco filed a prospectus on September 30, 2025, and Synovus and Pinnacle each filed a definitive proxy statement on September 30, 2025.  Synovus and Pinnacle each commenced mailing of the definitive joint proxy statement/prospectus to their respective shareholders on or about September 30, 2025.  INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT AND DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS (AND ANY OTHER DOCUMENTS THAT HAVE BEEN OR MAY BE FILED WITH THE SEC IN CONNECTION WITH THE TRANSACTION OR INCORPORATED BY REFERENCE INTO THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS) BECAUSE SUCH DOCUMENTS WILL CONTAIN IMPORTANT INFORMATION REGARDING THE PROPOSED TRANSACTION AND RELATED MATTERS.  Investors and security holders may obtain free copies of these documents and other documents filed with the SEC by Synovus, Pinnacle or Newco through the website maintained by the SEC at http://www.sec.gov or by contacting the investor relations department of Synovus or Pinnacle at:

Synovus Financial Corp.	Pinnacle Financial Partners, Inc.
33 West 14th Street	21 Platform Way South
Columbus, GA 31901	Nashville, TN 37203
Attention:  Investor Relations	Attention:  Investor Relations
InvestorRelations@Synovus.com (706) 641-6500	Investor.Relations@pnfp.com (615) 743-8219

Before making any voting or investment decision, investors and security holders of Synovus and Pinnacle are urged to read carefully the entire registration statement and definitive joint proxy statement/prospectus, including any amendments thereto, because they contain important information about the proposed transaction.  Free copies of these documents may be obtained as described above.

Participants in Solicitation

Synovus and Pinnacle and their respective directors and executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies from Synovus’ shareholders and Pinnacle’s shareholders in respect of the proposed transaction under the rules of the SEC. Information regarding Synovus’ directors and executive officers is available in Synovus’ proxy statement for its 2025 annual meeting of shareholders, filed with the SEC on March 12, 2025 (and available at https://www.sec.gov/ix?doc=/Archives/edgar/data/0000018349/000001834925000057/syn-20250312.htm) (the “Synovus 2025 Proxy”), under the headings “Corporate Governance and Board Matters,” “Director Compensation,”  “Proposal 1 Election of Directors,” “Executive Officers,” “Stock Ownership of Directors and Named Executive Officers,” “Executive Compensation,” “Compensation and Human Capital Committee Report,” “Summary Compensation Table,” and “Certain Relationships and Related Transactions,” and in Synovus’ Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 21, 2025 (and available at https://www.sec.gov/ix?doc=/Archives/edgar/data/0000018349/000001834925000049/syn-20241231.htm), and in other documents subsequently filed by Synovus with the SEC, which can be obtained free of charge through the website maintained by the SEC at http://www.sec.gov. Any changes in the holdings of Synovus’ securities by Synovus’ directors or executive officers from the amounts described in the Synovus 2025 Proxy have been or will be reflected on Initial Statements of Beneficial Ownership of Securities on Form 3 or on Statements of Change in Ownership on Form 4 filed with the SEC subsequent to the filing date of the Synovus 2025 Proxy and are available at the SEC’s website at www.sec.gov. Information regarding Pinnacle’s directors and executive officers is available in Pinnacle’s proxy statement for its 2025 annual meeting of shareholders, filed with the SEC on March 3, 2025 (and available at https://www.sec.gov/ix?doc=/Archives/edgar/data/1115055/000111505525000063/pnfp-20250303.htm) (the “Pinnacle 2025 Proxy”), under the headings “Environmental, Social and Corporate Governance,”  “Proposal 1 Election of Directors,” “Information About Our Executive Officers,” “Executive Compensation,” “Security Ownership of Certain Beneficial Owners and Management,” and “Certain Relationships and Related Transactions,” and in Pinnacle’s Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 25, 2025 (and available at https://www.sec.gov/ix?doc=/Archives/edgar/data/1115055/000111505525000042/pnfp-20241231.htm), and in other documents subsequently filed by Pinnacle with the SEC, which can be obtained free of charge through the website maintained by the SEC at http://www.sec.gov. Any changes in the holdings of Pinnacle’s securities by Pinnacle’s directors or executive officers from the amounts described in the Pinnacle 2025 Proxy have been or will be reflected on Initial Statements of Beneficial Ownership of Securities on Form 3 or on Statements of Change in Ownership on Form 4 filed with the SEC subsequent to the filing date of the Pinnacle 2025 Proxy and are available at the SEC’s website at www.sec.gov.  Additional information regarding the interests of such participants is included in the definitive joint proxy statement/prospectus and will be included in other relevant materials to be filed with the SEC.

No Offer or Solicitation

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

-3-

FAQ

What did Synovus (SNV) file and why?

A Rule 425 communication about its proposed merger with Pinnacle, highlighting the effective S‑4 for Steel Newco Inc. and the joint proxy/prospectus.

When was the Newco S-4 declared effective?

The registration statement on Form S‑4 was declared effective on September 30, 2025.

What materials were sent to shareholders of SNV and Pinnacle?

A definitive joint proxy statement/prospectus, with mailing commenced on or about September 30, 2025.

What key risks are highlighted for the merger?

Risks include achieving cost savings and synergies, integration challenges and costs, required shareholder and governmental approvals, potential dilution, and market conditions.

Does this filing offer or solicit the sale of securities?

No. It states it is not an offer to sell or a solicitation to buy securities.

Where can investors access the merger documents?

Free copies are available via the SEC’s website at www.sec.gov or through Synovus and Pinnacle investor relations.

What stock is being registered in connection with the merger?

Shares of Newco common stock to be issued to Synovus and Pinnacle shareholders.