8. Fair Value Measurement

Investment in Securities at Fair Value

The Company elected the fair value option for the securities in its investment portfolio. The fair value is based on quoted market prices, when available. When a quoted market price is not readily available, the Company uses the market price from its last sale of similar assets. The cash and cash equivalents held by the Company are categorized as Level 1 investments as quoted market prices are readily available for these investments. All other investments in the investment portfolio are categorized as Level 2 investments as inputs utilized to fair value these securities are either directly or indirectly observable, such as the market price from the last sale of similar assets.

The unrealized gains and losses on the available-for-sale securities, represented by change in the fair value of the investment portfolio, are reported in earnings. Since the investment in the available-for-sale securities are already measured at fair value, no separate credit losses would be recorded in the financials.

For the year-ended December 31, 2025 and 2024, the Company recognized a $3.1 million and $3.8 million gain related to the change in fair value in its available for sale securities recorded as a Change in fair value of assets and liabilities, net in its consolidated statements of operations.

Other Investments Held at Fair Value

COMPASS Pathways plc

The Company determines the fair value of its COMPASS investment by taking the publicly available share price as of the balance sheet date multiplied by the number of shares the Company holds. There are no non-observable inputs in determining the fair value. For the years ended December 31, 2025 and 2024, the Company recognized a $18.3 million gain and a $39.4 million loss within Change in fair value of assets and liabilities, net, respectively.

Beckley Psytech Additional Warrants

Prior to the Company’s acquisition of Beckley Psytech and as described in Note 6, Investments, the Company determined that the Additional Warrants meet the definition of a derivative instrument under ASC 815 and recorded the Additional Warrants at fair value with subsequent changes in fair value being reflected through the consolidated statements of operations in Change in fair value of assets and liabilities, net.

At the Acquisition Date, Beckley Psytech became a wholly owned subsidiary and the Additional Warrants no longer exist, resulting in the Additional Warrants having no value as of December 31, 2025. As of December 31, 2024, the Additional Warrants had a fair value of $2.8 million recognized in Other investments held at fair value in the consolidated balance sheet.

The significant unobservable inputs that are included in the valuation of the Additional Warrants as of December 31, 2024 are (i) probability of issuances under the deferred equity arrangement of 55%-80%, and (ii) volatility of 95%.

IntelGenx Technologies Corp.

IntelGenx Equity Investments

As described in Note 6, Investments, prior to the completion of the Company's acquisition of IGX in October 2024, the Company's investment in IntelGenx included IntelGenx Common Stock, Warrants, and Call Option Units for which it qualified for and elected the fair value option. The Company determined that the Warrants and the Call Option Units did not meet the definition of a derivative instrument under ASC 815. The Company classified the IntelGenx Common Stock as Level 2 assets and the Warrants and the Call Option as Level 3 assets in the fair value hierarchy. The Warrants and Call Option were measured at fair value on a quarterly basis and any changes in the fair value were recorded as Change in fair value of assets and liabilities, net, a component of other expense, net in the consolidated statements of operations.

Considering the aforementioned facts and circumstances in Note 4, Acquisitions, and Note 6, Investments, the Company estimated zero fair value attributable to the IntelGenx Common Stock, Warrants, and Call Option Units as of December 31, 2025 and 2024. For the year ended December 31, 2024, the Company recognized losses of $5.2 million and $1.4 million within Change in fair value of assets and liabilities, net relating to the Call Option Units and the Warrants, respectively, in its consolidated statements of operations.

IntelGenx Notes Receivable

As described in Note 7, Notes Receivable, prior to October 2024, the Company's notes receivable with IntelGenx included the IntelGenx Term Loan, the DIP Loan, and the IntelGenx Unsecured Debt for which it qualified for and elected the fair value option. The fair value of these instruments were estimated based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy.

As described in Note 4, Acquisitions, above, the Company made a Stalking Horse bid for IntelGenx as they sought protection from creditors under the CCAA. The Company's bid was to acquire certain assets and liabilities of IntelGenx in exchange for the discharge of all senior secured debt payable by IntelGenx, which included the DIP Loan and the IntelGenx Term Loan. The underlying collateral of such senior secured debt was determined to be the net assets and liabilities of IGX as acquired by the Company and as included in the Company's Stalking Horse bid. Accordingly, the Company has estimated the fair value of the underlying collateral, which included the fair value of the acquired intangible assets, based on a probability adjusted forecasted revenue and expenses and a discount rate of 12.5%. The Company adjusted the fair value of the DIP Loan to agree to this determined fair value of the net assets and liabilities acquired. As of the Company's acquisition date of IGX in October 2024, the fair value of the DIP Loan was $5.7 million and the fair value of the IntelGenx Term Loan was zero immediately prior to these receivables being discharged as consideration.

Considering relevant facts and circumstances, the Company estimated the fair value attributable to the various notes receivables with IntelGenx based on the remaining fair value of the underlying collateral. As the IntelGenx Unsecured Debt was not secured by the underlying collateral and IntelGenx continues to go through bankruptcy, the Company determined the fair value of IntelGenx Unsecured Debt to be zero as of December 31, 2025 and 2024, respectively.

For the year ended December 31, 2024, the Company recognized losses of $2.9 million, an immaterial amount, and $10.9 million in Change in fair value of assets and liabilities, net in its consolidated statements of operations relating to the IntelGenx Term Loan, the DIP Loan, and the IntelGenx Unsecured Debt, respectively.

Digital Assets

In 2025, the Company invested in Bitcoin to diversify its treasury investment strategy. Under ASC 350-60, the Company’s digital assets are measured at fair value based on quoted prices on active exchanges, and are therefore categorized as Level 1 investments in the fair value hierarchy. The Company recognizes changes in the fair value of its digital assets as gains or losses in Change in fair value of digital assets on the Company's consolidated statements of operations during the period in which they occur.

For the year ended December 31, 2025, the Company recognized a $1.2 million loss, related to the change in fair value in its Bitcoin holding, which is recognized as a Change in fair value of digital assets, net in its consolidated statements of operations.

Convertible Promissory Note

As described in Note 14, Debt, in December 2023 and April 2024, the Company entered into subscription agreements with each of a noteholder and a related party noteholder, respectively, (together the "Subscription Agreements") whereby each of the noteholder and the related party noteholder exchanged their ATAI Life Sciences AG (now known as ATAI Life Sciences GmbH) notes, into the same principal amount of new convertible notes issued by the Company (the "New Convertible Notes"). The exchange resulted in the New Convertible Notes conversion option no longer meeting the equity classification criteria. Accordingly, at the time of the exchange modification, the Company bifurcated the conversion option and reclassified the conversion option fair value from equity to a liability, which was included in Short-term convertible promissory notes and derivative liability and Short-term convertible promissory notes and derivative liability - related party, respectively, in the consolidated balance sheets. In September 2025 the noteholder and related party noteholder each exercised the conversion feature of the New Convertible Notes and converted all of their respective New Convertible Notes into common stock of the Company.

The conversion option was measured at fair value on a quarterly basis as well as immediately prior to conversion with any changes in the fair value recognized as Change in fair value of assets and liabilities, net, a component of other expense, net in the consolidated statements of operations. For the years ended December 31, 2025 and 2024, the Company recorded losses of $20.3 million and $3.4 million, respectively, as a result of the change in fair value of the New Convertible Notes.

Immediately prior to conversion, the conversion option fair value was estimated utilizing the Company’s stock price on the date of conversion. Prior to conversion, the fair value of the conversion option was estimated utilizing the Black-Scholes option pricing model and was classified as Level 3 in the fair value hierarchy based on the nature of the inputs and valuation techniques. The Black-Scholes option pricing model was based on the estimated market value of the underlying common stock at the valuation measurement date, the remaining contractual term of the conversion feature, risk-free interest rates, expected dividends, and expected volatility of the price of the underlying common stock. The expected volatility was based upon the historical volatility of daily lognormal returns on atai shares.

A significant input that was included in the valuation of the conversion feature as of December 31, 2024 was volatility of 75%.

Contingent Consideration Liability - Related Party

The contingent consideration liability - related party in the fair value measurement table above relates to milestone and royalty payments in connection with the acquisition of Perception Neuroscience Holdings, Inc. (“Perception”) in 2018. The fair value of the contingent consideration liabilities—related parties was determined based on significant inputs not observable in the market, which represent Level 3 measurements within the fair value hierarchy. The fair value of the contingent milestone and royalty liabilities was estimated based on the discounted cash flow valuation technique. The technique considered the following unobservable inputs:

The fair value of the Perception contingent milestone and royalty liabilities could change in future periods depending on prospects for the outcome of R-Ketamine milestone meetings with the FDA or other regulatory authorities, and whether the Company realizes a significant increase or decrease in sales upon commercialization.

The most significant assumptions in the discounted cash flow valuation technique that impacts the fair value of the milestone contingent consideration are the projected milestone timing and the probability of the milestone being met. Further, significant assumptions in the discounted cash flow that impacts the fair value of the royalty contingent consideration are the projected revenue over ten years, the timing of royalties on commercial revenue, and the probability of success rate for a commercial R-Ketamine product. As of December 31, 2025, the Company expects that the revenue projection over the ten year term is de minimis and no longer includes the contingent royalty payment in the total fair value of the contingent consideration.

The valuations as of December 31, 2025 and 2024, respectively, used inputs that were unobservable inputs with the most significant being the discount rates for clinical milestones and probability of success estimates over the following ten years, which represent Level 3

measurements within the fair value hierarchy. The discount rates used for clinical milestones were 13% and 11.6% for the valuations as of December 31, 2025 and 2024, respectively, and the probability of success for the milestones was 5% for December 31, 2025 and 2024.

A significant input that was included in the valuation of the Contingent consideration liability - related party as of December 31, 2024 was the discount rate for royalties on projected commercial revenue of 3.8%-4.3% and a probability of success rate of 5%.

The fair value of the contingent milestone and royalty liabilities for Perception was estimated to be $0.1 million and $0.1 million as of December 31, 2025 and 2024, respectively.

Contingent Consideration Liabilities

The contingent consideration liabilities in the fair value table above relates to milestone payments in connection with the acquisition of DemeRx IB, Inc. ("DemeRx"), and TryptageniX. The fair value of the contingent consideration liabilities were determined based on significant inputs not observable in the market, which represent Level 3 measurements within the fair value hierarchy. The fair value of the contingent milestone and royalty liabilities was estimated based on the discounted cash flow valuation technique. The technique considered the following unobservable inputs:

DemeRx

In October 2023, the Company and DemeRx, Inc. entered into a Stock Purchase and Framework Agreement which resulted in the Company's acquisition of DemeRx, Inc.’s equity ownership of DemeRx IB (the “Stock Purchase”), in exchange for consideration that included, among other items, earn-out consideration of up to an additional $8.0 million payable to DemeRx, Inc. contingent upon the achievement of certain development milestones directly related to DemeRx’s oral capsule formulation of ibogaine (“DMX-1002”) program. The earn-out consideration was recorded at fair value in contingent consideration as a liability under ASC 480 and the fair value is adjusted each quarter and reflected in other income and expense in the statements of operations.

The fair value of the DemeRx contingent milestone could change in future periods depending on prospects for the outcome of ibogaine milestone meetings with the FDA or other regulatory authorities. The most significant assumptions in the discounted cash flow valuation technique that impacts the fair value of the milestone contingent consideration are the projected milestone timing and the probability of the milestone being met. The valuations as of December 31, 2025 and 2024 used inputs that were unobservable inputs with the most significant being the discount rates clinical milestones and probability of success, which represent Level 3 measurements within the fair value hierarchy.

For the years ended December 31, 2025 and 2024, the fair value of the contingent milestone for DemeRx was estimated to be $0.2 million and $0.2 million, respectively.

TryptageniX

The fair value of the contingent liability for TryptageniX was estimated to be an immaterial amount as of both December 31, 2025 and 2024, respectively. The contingent liability is comprised of research and development milestone success fee payments and royalties payments. The fair value of the success fee liability was estimated based on the scenario-based method within the income approach. The fair value of the contingent liability for TryptageniX was determined based on significant unobservable inputs, including the discount rate, estimated probabilities of success, and timing of achieving certain clinical milestones. The fair value of the royalties liability was determined to be de minimis as the products are in the early stages of development. The Company will continue to assess the appropriateness of the fair value of the contingent liability as the products continue through development.

Pre-funded Warrant Liabilities

On June 2, 2025, the Company entered into the subscription agreements, dated as of June 2, 2025 (the “June 2025 Subscription Agreements”) relating to the purchase (the “June 2025 PIPE Financing”) by the investors party thereto of (i) 9,993,341 common stock of the Company with a nominal value of €0.10 per share for a purchase price of $1.84 per share, and (ii) a pre-funded warrant to purchase

6,311,006 common stock with an exercise price of $0.01 (the “June 2025 Pre-Funded Warrants”), for a purchase price of $1.84 per common share underlying the June 2025 Pre-Funded Warrants less the exercise price for the June 2025 Pre-Funded Warrants of $0.01 per share, resulting in aggregate gross proceeds to the Company from the June 2025 PIPE Financing of approximately $29.9 million. See Note 15, Stockholders’ Equity, for further details regarding the June 2025 PIPE Financing.

On July 1, 2025, the Company entered into subscription agreements, dated as of July 1, 2025 (“July 2025 Subscription Agreements”), relating to the purchase (the “July 2025 PIPE Financing”) by the investors party thereto of 18,264,840 common stock in the capital of the Company with a nominal value of €0.10 per share for a purchase price of $2.19 per share and a pre-funded warrant to purchase 4,566,210 common stock with an exercise price of $0.01 (the “July 2025 Pre-Funded Warrant”) for a purchase price of $2.19 per common share underlying the July 2025 Pre-Funded Warrant less the exercise price for the July 2025 Pre-Funded Warrant of $0.01 per share, resulting in aggregate gross proceeds to the Company from the July 2025 PIPE Financing of approximately $50.0 million. See Note 15, Stockholders’ Equity, for further details regarding the July 2025 PIPE Financing.

Under ASC 815, the Company recognizes the June and July 2025 Pre-Funded Warrants, respectively, at fair value as Pre-funded warrant liabilities within its consolidated balance sheet. The change in fair value of the Company's Pre-Funded Warrants is recognized as a Change in fair value of assets and liabilities, net in its consolidated statements of operations. The fair value of these instruments are estimated based on the Company's stock price observable in the market less the exercise price, which represents a Level 1 measurement within the fair value hierarchy. For the year ended December 31, 2025, the Company recognized a $22.9 million loss related to the change in fair value of the Pre-funded June and July Warrants.