Plum IV Cuts CTR Merger Valuation 30% to $3.15 Billion
Deal Stress
Company Background
Plum Acquisition Corp. IV (Nasdaq: PLMK) is a special purpose acquisition company with approximately $258 million in market capitalization whose sole strategic focus is completing a business combination with Controlled Thermal Resources Holdings Inc. CTR is a development-stage California company advancing the Hell's Kitchen geothermal energy and critical minerals project in Imperial County's Salton Sea region.
CTR has not yet generated revenue. The company says it has raised and invested approximately $285 million in private capital to date, holds a Conditional Use Permit for Stage 1 construction, and has entered strategic partnerships with Baker Hughes and Aquatech for its geothermal power and direct lithium extraction process. At full build-out across seven planned stages, CTR projects up to 650 megawatts of baseload power and roughly 100,000 metric tons per year of lithium carbonate—but Stage 1, targeting 50 MW and 25,000 metric tons per year of lithium, has not yet broken ground.
Plum IV held approximately $184.5 million in trust as of July 9, 2026. Shareholders were asked to vote on July 10, 2026 on an extension giving the SPAC until January 16, 2027 to close a business combination, with the option for further monthly extensions through July 16, 2027.
What Was Disclosed
The implied valuation of CTR used to calculate the merger consideration fell from $4.5 billion to $3.15 billion—a reduction of 30%—under a second amendment to the business combination agreement signed on July 6, 2026. The filing provides no explanation for the reduction. Potential earnout shares issuable to CTR shareholders were simultaneously cut from 100 million to 70 million, with each of the eight individual earnout tranches reduced proportionally from 12.5 million to 8.75 million shares.
The outside closing date was extended from December 31, 2026 to April 30, 2027, a four-month delay. The deadline for making required antitrust filings was pushed from July 31, 2026 to September 30, 2026. The amendment also raised the maximum number of shares that can be issued as non-redemption incentives—payable either to sponsor Plum Partners IV, LLC as reimbursement for founder shares, or directly to shareholders agreeing not to redeem—from 2 million to 3 million shares.
No Form S-4 registration statement has been filed with the SEC. The agreement contemplates that one will be filed, after which a definitive proxy statement will be mailed to shareholders ahead of a vote on the merger.
Why It Matters
The Business Combination Agreement was signed on March 8, 2026—the second amendment arrived less than four months later. A first amendment, signed May 15, 2026, extended only procedural deadlines: when CTR was required to deliver audited financial statements for the proxy, when antitrust filings had to be made, and when certain material consents were due. That amendment left the economic terms intact. The second amendment rewrites the price, the earnout structure, and the timeline, not merely the administrative schedule.
The original March 2026 investor presentation pegged CTR's pro-forma enterprise value at approximately $4.7 billion and modeled the financing structure assuming 0% shareholder redemptions from the roughly $180 million trust. The decision to raise the non-redemption share cap from 2 million to 3 million indicates the parties are now more actively working to limit redemptions—a condition that has grown more material as the deal's timeline and valuation have both shifted.
CTR remains a pre-revenue, pre-construction project. Closing the merger, completing a PIPE raise, and securing project debt are all conditions that still lie ahead. With antitrust filings not yet submitted and no registration statement on file, the new April 30, 2027 outside date represents the minimum runway the parties believe they need to reach a vote.