Prosperity Bancshares shares are higher today as investors react to progress on the company’s pending acquisition of Stellar Bancorp. The key catalyst is an S-4 registration statement filing that includes a preliminary proxy statement/prospectus for the transaction, signaling the deal has moved into the formal SEC-review and shareholder-solicitation phase. (stocktitan.net)

Prosperity agreed to acquire Stellar in a cash-and-stock transaction that was valued at roughly $2.0 billion at announcement. Stellar shareholders are slated to receive $11.36 in cash plus 0.3803 shares of Prosperity common stock per Stellar share, with the transaction expected to close in Q2 2026 subject to approvals and other conditions. (s203.q4cdn.com)

The S-4 proxy/prospectus package is a key gating item for large bank mergers because it’s used to register the Prosperity shares to be issued and to solicit Stellar shareholder approval. Even though the document is labeled preliminary and subject to completion, filing it can reduce “timeline uncertainty” and refocus attention on execution, synergy potential, and the regulatory path to closing. (stocktitan.net)

Next milestones include SEC comments and amendments to the S-4, setting the Stellar shareholder meeting date, and updates on regulatory approvals ahead of the targeted second-quarter 2026 closing window. Investors will also monitor Prosperity’s upcoming quarterly results for any changes in credit trends, net interest margin trajectory, and capital flexibility as the company works through multiple integration efforts. (morningstar.com)