December 20, 2025 — Amicus Therapeutics, Inc. (NASDAQ: FOLD) is suddenly trading like a classic merger-arbitrage stock after BioMarin Pharmaceutical (NASDAQ: BMRN) agreed to acquire the company in an all-cash deal valued at roughly $4.8 billion. BioMarin’s offer of $14.50 per share sparked a sharp re-pricing of Amicus shares, which have been hovering just below the bid as investors weigh deal timing, closing risk, and what the buyout means for Amicus’ two commercial rare-disease franchises—Galafold (Fabry disease) and Pombiliti + Opfolda (Pompe disease).
Below is a detailed breakdown of the latest news (as of 20.12.2025), plus the most relevant forecasts and analyst angles that were shaping expectations right before the acquisition changed the conversation.
What happened to Amicus Therapeutics stock on December 19–20, 2025?
Amicus shares were quoted around $14.18 in the latest data available, up roughly 30% from the prior close—an immediate market response that is typical when a cash acquisition price becomes the new “gravity well” for a target stock. Trading volume also surged dramatically, reflecting institutions repositioning and event-driven funds moving in. Reuters
The key point for readers: FOLD is no longer being priced primarily on quarterly revenue beats or pipeline optionality. In the near term, it’s being priced on (1) the $14.50 cash consideration and (2) the market’s best guess at the probability and timeline of closing.
The headline news: BioMarin’s $14.50-per-share all-cash acquisition
Deal terms and timeline
BioMarin and Amicus announced a definitive agreement under which BioMarin will acquire Amicus for $14.50 per share in cash—a premium of 33% to Amicus’ prior close, and premiums versus 30- and 60-day volume-weighted averages as disclosed by the companies. The transaction has been unanimously approved by both boards, with Amicus’ board recommending shareholders vote in favor. Closing is targeted for Q2 2026, subject to customary conditions including Amicus shareholder approval and antitrust review (including the U.S. Hart-Scott-Rodino process).
Financing (and why it matters to the spread)
BioMarin stated the transaction is not subject to financing conditions. The company plans to fund the purchase using cash on hand plus roughly $3.7 billion in non-convertible debt financing, supported by a bridge commitment. Reuters also reported BioMarin had about $2 billion in cash and investments as of the end of September.
Why this matters for FOLD holders: when a deal is “not subject to financing,” one common failure point is removed—which can tighten the trading gap between the target’s market price and the offer price.
Why BioMarin is paying up: Two marketed rare-disease drugs with momentum
BioMarin is buying Amicus for what investors generally love in biotech: real products, real revenue, and growing franchises.
In the acquisition announcement, the companies said Galafold and Pombiliti + Opfolda generated $599 million in net product revenues over the past four quarters. BioMarin is positioning these therapies as high-growth assets that can scale further through its global commercial footprint and in-house manufacturing capabilities.
Amicus CEO Bradley Campbell also highlighted that Amicus’ therapies have impacted more than 3,400 patients worldwide, a figure that helps frame the current commercial base BioMarin is acquiring.
A second, underappreciated catalyst: Galafold U.S. patent litigation settlements and 2037 exclusivity expectations
Alongside the deal announcement, the companies disclosed that Amicus resolved patent litigation tied to generic challenges to Galafold (migalastat) in the U.S., including litigation involving Aurobindo and Lupin. Based on those settlements, the companies said U.S. exclusivity for Galafold is expected through January 2037.
For stock watchers, this is not a minor footnote. Extending (or clarifying) the runway before generic entry can materially change how investors model:
- peak sales and durability for Galafold,
- long-term cash flows supporting pipeline investment,
- and strategic attractiveness to acquirers.
In other words: the deal news and the IP news reinforce each other.
The latest fundamentals (pre-deal): Amicus’ Q3 2025 results, profitability milestone, and 2025 guidance
Even though the acquisition is now the main driver, the financial trajectory leading into the deal helps explain why Amicus became buyable at a premium.
In its third-quarter 2025 update, Amicus reported:
- Total revenues of $169.1 million for Q3 2025
- Galafold Q3 net product sales of $138.3 million
- Pombiliti + Opfolda Q3 net product sales of $30.7 million
- GAAP net income of $17.3 million (a notable swing versus a year-ago GAAP loss)
- Cash, cash equivalents, and marketable securities of $263.8 million at September 30, 2025
Amicus also reiterated 2025 guidance in that same release, including:
- Total revenue growth (constant exchange rates) of 15% to 22%
- Galafold revenue growth of 10% to 15%
- Pombiliti + Opfolda revenue growth of 50% to 65%
- Gross margin “mid 80%”
- Non-GAAP operating expenses of $380M to $400M
- Expectation of positive GAAP net income during H2 2025
This mix—double-digit growth plus a turn into GAAP profitability—helped shift the narrative around Amicus from “commercial-stage but cash-burning biotech” to something closer to “scaled rare-disease company with operating leverage,” which is exactly the type of asset large pharma and larger biotech tend to buy.
Pipeline optionality that comes with the deal: DMX-200 and the ACTION3 Phase 3 program
BioMarin is also acquiring Amicus’ U.S. rights to DMX-200, a Phase 3-stage investigational small molecule for focal segmental glomerulosclerosis (FSGS), a rare kidney disease.
And there’s fresh, time-relevant news here:
On December 15, 2025, Dimerix (Amicus’ U.S. partner) announced that the ACTION3 Phase 3 trial for DMX-200 completed recruitment, including dosing of the 286th adult patient, with the trial evaluating DMX-200’s efficacy and safety over a two-year treatment period. The company also noted ongoing FDA feedback discussions around endpoints and potential accelerated approval approaches.
Why it matters for FOLD investors today: DMX-200 is the kind of “free call option” that can sweeten the strategic logic of a deal. It may not be what sets the cash price, but it can influence how confident an acquirer feels about long-term value creation after closing.
Analyst forecasts and price targets: what Wall Street expected before the buyout
Once a cash deal is announced, traditional 12-month price targets become less influential (because the upside is capped by the offer price unless a competing bid emerges). But it’s still useful to know how the Street was framing Amicus’ upside immediately beforehand.
A Nasdaq.com article citing Fintel data reported that Citigroup initiated coverage on December 17, 2025 with a Buy rating, and that as of December 6, 2025, the average one-year analyst price target cited there was $16.78 per share (with a stated range of $11.11 to $23.10), implying substantial upside from the then-recent pre-deal trading levels.
In plain English: the stock was already being viewed as undervalued by at least some analysts, and the BioMarin bid arrived right on top of that improving sentiment—after a year of increasingly “real company” execution (revenue growth, profitability, and expansion of Pompe commercialization).
What investors will watch next (and why FOLD may trade “stuck” near $14.50)
With FOLD around $14.18 versus a $14.50 cash offer, the remaining gap is roughly $0.32 per share. That gap is the market’s live, constantly-updated expression of:
- closing risk (regulatory, shareholder vote, timing),
- time value (money today vs. money in Q2 2026),
- and any perceived chance of a revised offer (usually low unless new information appears).
Key gating items are clearly spelled out by the companies: shareholder approval, antitrust clearance, and other customary conditions, with a targeted close in Q2 2026.
One subtle but important detail in the announcement: BioMarin said the deal is expected to be accretive to non-GAAP diluted EPS within the first 12 months post-close, and “substantially accretive” beginning in 2027—language that signals BioMarin believes it can absorb Amicus without years of profit dilution. SEC+1
Bottom line for December 20, 2025: Amicus stock is now a deal story—with fundamentals as the backstop
As of 20.12.2025, the center of gravity for Amicus Therapeutics stock is the BioMarin acquisition at $14.50 per share, plus the closing path into Q2 2026.
The reason this deal landed (and why it landed with a meaningful premium) is that Amicus entered the announcement with:
- two marketed rare-disease products generating $599 million over the last four quarters,
- improving profitability (including a GAAP profitable quarter in Q3 2025),
- reiterated growth guidance into year-end,
- and extra “option value” in DMX-200 as the ACTION3 Phase 3 trial moves forward. SEC+2SEC+2
From here, FOLD’s day-to-day movement will likely be less about traditional biotech volatility and more about the quiet mechanics of deal completion—until something changes (regulatory surprises, a competing bid, or material new disclosures in proxy materials).
