2. Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Accounting Principles. The consolidated financial statements and accompanying notes are prepared on the accrual basis of accounting in accordance with generally accepted accounting principles in the United States of America ("U.S. GAAP").

Principles of Consolidation. The accompanying consolidated financial statements include the accounts of Acacia and its wholly and majority-owned and controlled subsidiaries. Material intercompany transactions and balances have been eliminated in consolidation.

Noncontrolling interests in Acacia’s majority-owned and controlled operating subsidiaries (“noncontrolling interests”) are separately presented as a component of stockholders’ equity. Consolidated net income or (loss) is adjusted to include the net (income) or loss attributed to noncontrolling interests in the consolidated statements of operations. Refer to the accompanying consolidated statements of Series A redeemable convertible preferred stock and stockholders’ equity for total noncontrolling interests.

In 2020, in connection with the transaction with Link Fund Solutions Limited, which is more fully described in Note 17, the Company acquired equity securities of Malin J1 Limited (“MalinJ1”). MalinJ1 is included in the Company’s consolidated financial statements because the Company, through its interest in the equity securities of MalinJ1, has the ability to control the operations and activities of MalinJ1. Viamet HoldCo LLC, a Delaware limited liability company and wholly-owned subsidiary of Acacia (see Note 17), is the majority shareholder of MalinJ1.

A wholly owned subsidiary of Acacia is the general partner of the Acacia Intellectual Property Fund, L.P. (the “Acacia IP Fund”), which was formed in August 2010. The Acacia IP Fund is included in the Company’s consolidated financial statements since 2010, as Acacia’s wholly owned subsidiary, as the general partner, has the ability to control the operations and activities of the Acacia IP Fund. The Acacia IP Fund was terminated as of December 31, 2017 and dissolved in 2020.

Revenue Recognition. Revenue is recognized upon transfer of control of promised bundled IP rights (hereinafter “IP Rights”) and other contractual performance obligations to licensees in an amount that reflects the consideration we expect to receive in exchange for those IP Rights. Revenue contracts that provide promises to grant the right to use IP Rights as they exist at the point in time at which the IP Rights are granted, are accounted for as performance obligations satisfied at a point in time and revenue is recognized at the point in time that the applicable performance obligations are satisfied and all other revenue recognition criteria have been met.

For the periods presented, revenue contracts executed by the Company primarily provided for the payment of contractually determined, one-time, paid-up license fees in consideration for the grant of certain IP Rights for patented technologies owned or controlled by Acacia (“Paid-up Revenue Agreements”). Revenues also included license fees from sales-based revenue contracts, the majority of which were originally executed in prior periods, which provide for the payment of quarterly license fees based on quarterly sales of applicable product units by licensees (“Recurring Revenue Agreements”). Revenues may also include court ordered settlements or awards related to our patent portfolio ("Other Settlements") or sales of our patent portfolio ("Sales"). IP Rights granted included the following, as applicable: (i) the grant of a non-exclusive, retroactive and future license to manufacture and/or sell products covered by patented technologies, (ii) a covenant-not-to-sue, (iii) the release of the licensee from certain claims, and (iv) the dismissal of any pending litigation. The IP Rights granted were perpetual in nature, extending until the legal expiration date of the related patents. The individual IP Rights are not accounted for as separate performance obligations, as (i) the nature of the promise, within the context of the contract, is to transfer combined items to which the promised IP Rights are inputs and (ii) the Company's promise to transfer each individual IP right described above to the customer is not separately identifiable from other promises to transfer IP Rights in the contract.

Since the promised IP Rights are not individually distinct, the Company combined each individual IP right in the contract into a bundle of IP rights that is distinct, and accounted for all of the IP Rights promised in the contract as a single performance obligation. The IP Rights granted were “functional IP rights” that have significant standalone functionality. Acacia's subsequent activities do not substantively change that functionality and do not significantly affect the utility of the IP to which the licensee has rights. Acacia’s operating subsidiaries have no further obligation with respect to the grant of IP Rights, including no express or implied obligation to maintain or upgrade the technology, or provide future support or services. The contracts provide for the grant (i.e., transfer of control) of the licenses, covenants-not-to-sue, releases, and other significant deliverables upon execution of the contract. Licensees legally obtain control of the IP Rights upon execution of the contract. As such, the earnings process is complete and revenue is recognized upon the execution of the contract, when collectability is probable and all other revenue recognition criteria have been met. Revenue contracts generally provide for payment of contractual amounts with 30-90 days of execution of the contract, or the end of the quarter in which the sale or usage occurs for Recurring Revenue Agreements. Contractual payments made by licensees are generally non-refundable.

For sales-based royalties, the Company includes in the transaction price some or all of an amount of estimated variable consideration to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Notwithstanding, revenue is recognized for a sales-based royalty promised in exchange for a license of IP Rights when the later of (i) the subsequent sale or usage occurs, or (ii) the performance obligation to which some or all of the sales-based royalty has been allocated has been satisfied. Estimates are generally based on historical levels of activity, if available.

Revenues from contracts with significant financing components (either explicit or implicit) are recognized at an amount that reflects the price that a licensee would have paid if the licensee had paid cash for the IP Rights when they transfer to the licensee. In determining the transaction price, the Company adjusts the promised amount of consideration for the effects of the time value of money. As a practical expedient, the Company does not adjust the promised amount of consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the entity transfers promised IP Rights to a customer and when the customer pays for the IP Rights will be one year or less.

In general, the Company is required to make certain judgments and estimates in connection with the accounting for revenue contracts with customers. Such areas may include identifying performance obligations in the contract, estimating the timing of satisfaction of performance obligations, determining whether a promise to grant a license is distinct from other promised goods or services, evaluating whether a license transfers to a customer at a point in time or over time, allocating the transaction price to separate performance obligations, determining whether contracts contain a significant financing component, and estimating revenues recognized at a point in time for sales-based royalties.

Revenues were comprised of the following for the periods presented:

	2020		2019
	(In thousands)
Paid-up Revenue Agreements	$	28,389	$	6,343
Recurring Revenue Agreements		1,393		4,903
Total Revenue	$	29,782	$	11,246

Refer to “Inventor Royalties and Contingent Legal Expenses” below for information on related direct costs of revenues.

Portfolio Operations. Cost of revenues include the costs and expenses incurred in connection with Acacia’s patent licensing and enforcement activities, including inventor royalties paid to original patent owners, contingent legal fees paid to external patent counsel, other patent-related legal expenses paid to external patent counsel, licensing and enforcement related research, consulting and other expenses paid to third-parties and the amortization of patent-related investment costs. These costs are included under the caption “Portfolio operations” in the accompanying consolidated statements of operations.

Inventor Royalties and Contingent Legal Expenses. Inventor royalties are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In certain instances, pursuant to the terms of the underlying inventor agreements, upfront advances paid to patent owners by Acacia’s operating subsidiaries are recoverable from future net revenues. Patent costs that are recoverable from future net revenues are amortized over the estimated economic useful life of the related patents, or as the prepaid royalties are earned by the inventor, as appropriate, and the related expense is included in amortization expense in the consolidated statements of operations. Any unamortized upfront advances recovered from net revenues are expensed in the period recovered and included in amortization expense in the consolidated statements of operations. There were no patent acquisition expenses for the years ended December 31, 2020 and 2019.

Contingent legal fees are expensed in the consolidated statements of operations in the period that the related revenues are recognized. In instances where there are no recoveries from potential infringers, no contingent legal fees are paid; however, Acacia’s operating subsidiaries may be liable for certain out of pocket legal costs incurred pursuant to the underlying legal services agreement.

Fair Value Measurements. U.S. GAAP defines fair value as the price that would be received for an asset or the exit price that would be paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date, and also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs, where available. Refer to Note 14 to our notes to consolidated financial statements for more information related to our fair value measurement.

Cash and Cash Equivalents. Acacia considers all highly liquid, trading securities with original maturities of three months or less when purchased to be cash equivalents. For the periods presented, Acacia’s cash equivalents are comprised of investments in AAA rated money market funds that invest in first-tier only securities, which primarily includes: domestic commercial paper, securities issued or guaranteed by the U.S. government or its agencies, U.S. bank obligations, and fully collateralized repurchase agreements. Acacia’s cash equivalents are measured at fair value using quoted prices that represent Level 1 inputs.

Long Term Restricted Cash. Long-term restricted cash relates to the proceeds received from the issuance of Series A redeemable convertible preferred stock (the “Series A Redeemable Convertible Preferred Stock”) which are held in an escrow account. The amounts are to be released to the Company upon, among other things, (i) the consummation of a suitable investment or acquisition by the Company or (ii) the conversion of Series A Redeemable Convertible Preferred Stock into common stock (see Note 16).

Trading Securities- Debt. Investments in debt securities are reported at fair value on a recurring basis, with related realized and unrealized gains and losses recorded in the consolidated statements of operations in other income (expense). Realized and unrealized gains and losses are recorded based on the specific identification method. Interest is included in other income (expense).

Trading Securities - Equity. Investments in equity securities are reported at fair value on a recurring basis, with related realized and unrealized gains and losses in the value of such securities recorded in the consolidated statements of operations in other income (expense). Dividend income is included in other income (expense).

Investment Securities – Private Equity. As the private company equity securities do not have readily determinable fair value, we have elected to report them under the measurement alternative. They are reported at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer. The fair values of the private company securities were estimated based on recent financing transactions and secondary market transactions and factoring in any adjustments for illiquidity or preference of these securities. Changes in fair value are reported in the consolidated statements of operations in other income (expense).

Impairment of Investments. Acacia evaluates its investments in marketable and private equity securities for potential impairment, employing a methodology on a quarterly basis that considers available quantitative and qualitative evidence. If the cost or carrying value of an investment exceeds its estimated fair value, the Company evaluates, among other factors, general market conditions, credit quality of instrument issuers, the duration and extent to which the fair value is less than cost, and the Company’s intent and ability to hold, or plans or ability to sell. Fair value is estimated based on publicly available market information or other estimates determined by management. Investments are considered to be impaired when a decline in fair value is estimated to be other-than-temporary. Acacia reviews impairments associated with its investments in these securities and determines the classification of any impairment as temporary or other-than-temporary. An impairment is deemed other-than-temporary unless (a) Acacia has the ability and intent to hold an investment for a period of time sufficient for recovery of its carrying amount and (b) positive evidence indicating that the investment’s carrying amount is recoverable within a reasonable period of time outweighs any evidence to the contrary. All available evidence, both positive and negative, is considered to determine whether, based on the weight of such evidence, the carrying amount of the investment is recoverable within a reasonable period of time. For investments classified as available-for-sale, unrealized losses that are other-than-temporary are recognized in the consolidated statements of operations.

Concentration of Credit Risks. Financial instruments that potentially subject Acacia to concentrations of credit risk are cash equivalents, trading securities and accounts receivable. Acacia places its cash equivalents and trading securities primarily in highly rated money market funds and investment grade marketable securities. Cash and cash equivalents are also invested in deposits with certain financial institutions and may, at times, exceed federally insured limits. Acacia has not experienced any significant losses on its deposits of cash and cash equivalents.

Three licensees individually accounted for 64%, 10% and 7%, respectively, of revenues recognized during the year ended December 31, 2020. Three licensees individually accounted for 43%, 22% and 15%, respectively, of revenues recognized during the year ended December 31, 2019. Two licensees individually represented approximately 62% and 21%, respectively, of accounts receivable at December 31, 2020. Two licensees individually represented approximately 70% and 17%, respectively, of accounts receivable at December 31, 2019.

For 2020 and 2019, 8% and 39%, respectively, of revenues were attributable to licensees domiciled in foreign jurisdictions, based on the jurisdiction of the entity obligated to satisfy payment obligations pursuant to the applicable revenue arrangement. The Company does not have any material foreign operations.

Acacia performs credit evaluations of its licensees with significant receivable balances, if any, and has not experienced any significant credit losses. Accounts receivable are recorded at the executed contract amount and generally do not bear interest. Collateral is not required. An allowance for doubtful accounts may be established to reflect the Company’s best estimate of probable losses inherent in the accounts receivable balance, and is reflected as a contra-asset account on the balance sheet and a charge to operating expenses in the consolidated statements of operations for the applicable period. The allowance is determined based on known troubled accounts, historical experience, and other currently available evidence. There was no allowance for doubtful accounts established for the periods presented.

Fair Value of Financial Instruments. The carrying value of cash and cash equivalents, restricted cash, accounts receivables, and current liabilities approximates their fair values due to their short-term maturities.

Property and Equipment. Property and equipment are recorded at cost. Major additions and improvements that materially extend useful lives of property and equipment are capitalized. Maintenance and repairs are charged against the results of operations as incurred. When these assets are sold or otherwise disposed of, the asset and related depreciation are relieved, and any gain or loss is included in the consolidated statements of operations for the period of sale or disposal. Depreciation and amortization is computed on a straight-line basis over the following estimated useful lives of the assets:

Furniture and fixtures	3 to 5 years
Computer hardware and software	3 to 5 years
Leasehold improvements	2 to 5 years (Lesser of lease term or useful life of improvement)

Rental payments on operating leases are charged to expense in the consolidated statements of operations on a straight-line basis over the lease term.

Patents. Patents include the cost of patents or patent rights (hereinafter, collectively “patents”) acquired from third-parties or obtained in connection with business combinations. Patent costs are amortized utilizing the straight-line method over their remaining economic useful lives, ranging from one to five years.

Leases. The Company adopted ASC 842 as of January 1, 2019, electing the practical expedient approaches. The primary impact of adopting ASC 842 for the Company was the recognition in the consolidated balance sheet of certain lease-related assets and liabilities for operating leases with terms longer than 12 months. Such amounts were not previously accounted for in the Company's consolidated balance sheets. The Company’s leases primarily consist of facility leases which are classified as operating leases. The Company assesses whether an arrangement contains a lease at inception. The Company recognizes a lease liability to make contractual payments under all leases with terms greater than twelve months and a corresponding right-of-use asset, representing its right to use the underlying asset for the lease term. Upon adoption of ASC 842 on January 1, 2019, the carrying value of certain lease related liabilities for its excess of lease payments over anticipated sublease income existing at that date, was offset against the related right-of-use assets. Lease expense is recognized on a straight-line basis over the lease term.

Investments at Fair Value. On an individual investment basis, Acacia may elect to account for investments in companies where the Company has the ability to exercise significant influence over operating and financial policies of the investee, at fair value. If the fair value option is applied to an investment that would otherwise be accounted for under the equity method of accounting, it is applied to all of the financial interests in the same entity that are eligible items (i.e., common stock and warrants).

Other Investments - equity method investments. Equity investments in common stock and in-substance common stock without readily determinable fair values in companies over which the Company has the ability to exercise significant influence, are accounted for using the equity method of accounting. Acacia includes its proportionate share of earnings and/or losses of its equity method investees in equity in earnings (losses) of investee in the consolidated statements of operations.

Investments in preferred stock with substantive liquidation preferences are accounted for at cost, (subject to impairment considerations, as described below, if any), as adjusted for the impact of changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. In-substance common stock is an investment in an entity that has risk and reward characteristics that are substantially similar to that entity's common stock. An investment in preferred stock with substantive liquidation preferences over common stock, is not substantially similar to common stock, and therefore is not considered in-substance common stock. A liquidation preference is substantive if the investment has a stated liquidation preference that is significant, from a fair value perspective, in relation to the purchase price of the investment. A liquidation preference in an investee that has sufficient subordinated equity from a fair value perspective is substantive because, in the event of liquidation, the investment will not participate in substantially all of the investee's losses, if any.

The initial determination of whether an investment is substantially similar to common stock is made on the initial date of investment if the Company has the ability to exercise significant influence over the operating and financial policies of the investee. That determination is reconsidered if (i) contractual terms of the investment are changed, (ii) there is a significant change in the capital structure of the investee, including the investee's receipt of additional subordinated financing, or (iii) the Company obtains an additional interest in an investment, resulting in the method of accounting for the cumulative interest being based on the characteristics of the investment at the date at which the Company obtains the additional interest. Refer to Notes 6 and 17 for additional information.

Impairment of Long-lived Assets. Acacia reviews long-lived assets and intangible assets for potential impairment annually (quarterly for patents) and when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss is recorded equal to the excess of the asset’s carrying value over its fair value. If an asset is determined to be impaired, the loss is measured based on quoted market prices in active markets, if available. If quoted market prices are not available, the estimate of fair value is based on various valuation techniques, including a discounted value of estimated future cash flows. In the event that management decides to no longer allocate resources to a patent portfolio, an impairment loss equal to the remaining carrying value of the asset is recorded. Refer to Note 5 for additional information.

Fair value is generally estimated using the “Income Approach,” focusing on the estimated future net income-producing capability of the patent portfolios over the estimated remaining economic useful life. Estimates of future after-tax cash flows are converted to present value through “discounting,” including an estimated rate of return that accounts for both the time value of money and investment risk factors. Estimated cash inflows are typically based on estimates of reasonable royalty rates for the applicable technology, applied to estimated market data. Estimated cash outflows are based on existing contractual obligations, such as contingent legal fee and inventor royalty obligations, applied to estimated license fee revenues, in addition to other estimates of out-of-pocket expenses associated with a specific patent portfolio’s licensing and enforcement program. The analysis also contemplates consideration of current information about the patent portfolio including, status and stage of litigation, periodic results of the litigation process, strength of the patent portfolio, technology coverage and other pertinent information that could impact future net cash flows.

Contingent Liabilities. The Company, from time to time, is involved in certain legal proceedings. Based upon consultation with outside counsel handling its defense in these matters and the Company’s analysis of potential outcomes, if the Company determines that a loss arising from such matters is probable and can be reasonably estimated, an estimate of the contingent liability is recorded in its consolidated financial statements. If only a range of estimated loss can be determined, an amount within the range that, based on estimates, assumptions and judgments, reflects the most likely outcome, is recorded as a contingent liability in the consolidated financial statements. In situations where none of the estimates within the estimated range is a better estimate of probable loss than any other amount, the Company records the low end of the range. Any such accrual would be charged to expense in the appropriate period. Litigation expenses for these types of contingencies are recognized in the period in which the litigation services were provided.

Certain of Acacia’s operating subsidiaries are often required to engage in litigation to enforce their patents and patent rights. In connection with any of Acacia’s operating subsidiaries’ patent enforcement actions, it is possible that a defendant may request and/or a court may rule that an operating subsidiary has violated statutory authority, regulatory authority, federal rules, local court rules, or governing standards relating to the substantive or procedural aspects of such enforcement actions. In such event, a court may issue monetary sanctions against Acacia or its operating subsidiaries or award attorney’s fees and/or expenses to a defendant(s), which could be material, and if required to be paid by Acacia or its operating subsidiaries, could materially harm the Company’s operating results and financial position.

Stock-Based Compensation. The compensation cost for all stock-based awards is measured at the grant date, based on the fair value of the award, and is recognized as an expense on a straight-line basis over the employee’s requisite service period (generally the vesting period of the equity award). The fair value of restricted stock and restricted stock units awards is determined by the product of the number of shares or units granted and the grant date market price of the underlying common stock. The fair value of each option award is estimated on the date of grant using a Black-Scholes option-pricing model. Forfeitures are accounted for as they occur.

Restricted stock units granted in September 2019 with market-based vesting conditions vest based upon the Company achieving specified stock price targets over a three-year period. The effect of a market condition is reflected in the estimate of the grant-date fair value of the options utilizing a Monte Carlo valuation technique. Compensation cost is recognized with a market-based vesting condition provided that the requisite service is rendered, regardless of when, if ever, the market condition is satisfied. Assumptions utilized in connection with the Monte Carlo valuation technique included: estimated risk-free interest rate of 1.38 percent; term of 3.00 years; expected volatility of 38 percent; and expected dividend yield of 0 percent. The risk-free interest rate was determined based on the yields available on U.S. Treasury zero-coupon issues. The expected stock price volatility was determined using historical volatility. The expected dividend yield was based on expectations regarding dividend payments.

Profits Interest Units (“Units”) are accounted for in accordance with Accounting Standards Codification (“ASC”) 718-10, “Compensation - Stock Compensation.” The Units vest as described at Note 9, and therefore, the vesting conditions do not meet the definition of service, market or performance conditions, as defined in ASC 718. As such, the Units are classified as liability awards. Liability classified awards are measured at fair value on the grant date and re-measured each reporting period at fair value until the award is settled. Compensation expense is adjusted each reporting period for changes in fair value prorated for the portion of the requisite service period rendered. Initially, compensation expense was recognized on a straight-line basis over the employee’s requisite service period (generally the vesting period of the equity award) which was five years. Upon full vesting of the award, which occurred during the three months ended September 30, 2017, previously unrecognized compensation expense was immediately recognized in the period, and will continue to be fully recognized for any changes in fair value, until the Units are settled. The Company has a purchase option to purchase the vested Units that are not otherwise forfeited after termination of continuous service. The exercise price of the purchase option is the fair market value of the Units on the date of termination of continuous service. At each reporting date, the value of the Units that are subject to the purchase option will be the measured at the fair value on the termination date. Non-cash stock compensation expense related to the Units is reflected in general and administrative expense in the accompanying consolidated statements of operations.

Series A Warrants. The fair value of the Series A warrants (the “Series A Warrants”) is estimated using a Black-Scholes option-pricing model. The fair value of the Series A Warrants as of December 31, 2020 was estimated based on the following assumptions: volatility of 29 percent, risk-free rate of 0.62 percent, term of 6.79 years and a dividend yield of 0 percent. The fair value of the Series A Warrants as of December 31, 2019 was estimated based on the following assumptions: volatility of 30 percent, risk-free rate of 1.85 percent, term of 7.79 years and a dividend yield of 0 percent. Refer to Notes 16 for additional information.

Series B Warrants. The fair value of the Series B Warrants is estimated using Monte Carlo valuation technique. The fair value of the Series B Warrants as of December 31, 2020 was estimated based on event probabilities of future exercise scenarios and the following weighted-average assumptions: (1) volatility of 29 percent, risk-free rate of 0.63 percent, term of 6.87 years, a dividend yield of 0 percent, and a discount for lack of marketability of 10 percent, and (2) volatility of 50 percent, risk-free rate of 0.12 percent, term of 1.65 years and a dividend yield of 0 percent, and a discount for lack of marketability of 10 percent. Refer to Notes 16 for additional information.

Embedded derivatives. Embedded derivatives that are required to be bifurcated from their host contract are valued separately from host instrument. A binomial lattice framework is used to estimate the fair value of the embedded derivative in the Series A Redeemable Convertible Preferred Stock. Refer to Notes 16 for additional information.

The binomial model utilizes the Tsiveriotis and Fernandes (“TF”) implementation in which a convertible instrument is split into two separate components: a cash-only component which is subject to the selected risk-adjusted discount rate and an equity component which is subject only to the risk-free rate. The model considers the (i) implied volatility of the value of our common stock, (ii) appropriate risk-free interest rate, (iii) credit spread, (iv) dividend yield, (v) dividend accrual (and a step-up in rates), and (vi) event probabilities of the various conversion and redemption scenarios.

The implied volatility of the Company’s common stock is estimated based on a haircut applied to the historical volatility. A volatility haircut is a concept used to describe a commonly observed occurrence in which the volatility implied by market prices involving options, warrants, and convertible debt is lower than historical actual realized volatility. The assumed base case term used in the valuation model is the period remaining until November 15, 2027 (the maturity date). The risk-free interest rate is based on the yield on the U.S. Treasury with a remaining term equal to the expected term of the conversion and early redemption options. The significant assumptions utilized in the Company’s valuation of the embedded derivative at December 31, 2020 are as follows: volatility of 29 percent, risk-free rate of 0.62 percent, a credit spread of 19 percent and a dividend yield of 0 percent. The significant assumptions utilized in the Company’s valuation of the embedded derivative at December 31, 2019 are as follows: volatility of 30 percent, risk-free rate of 1.86 percent, a credit spread of 25 percent and a dividend yield of 0 percent. The fair value measurement of the embedded derivative is sensitive to these assumptions and changes in these assumptions could result in a materially different fair value measurement.

Income Taxes. Income taxes are accounted for using an asset and liability approach that requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in Acacia’s consolidated financial statements or consolidated income tax returns. A valuation allowance is established to reduce deferred tax assets if all, or some portion, of such assets will more than likely not be realized, or if it is determined that there is uncertainty regarding future realization of such assets.

Under U.S. generally accepted accounting principles, a tax position is a position in a previously filed tax return or a position expected to be taken in a future tax filing that is reflected in measuring current or deferred income tax assets and liabilities. Tax positions are recognized only when it is more likely than not (likelihood of greater than 50%), based on technical merits, that the position will be sustained upon examination. Tax positions that meet the more likely than not threshold are measured using a probability weighted approach as the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement.

Segment Reporting. Acacia uses the management approach, which designates the internal organization that is used by management for making operating decisions and assessing performance as the basis of Acacia’s reportable segments. The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions.

Use of Estimates. The preparation of financial statements in conformity with generally accepted accounting principles in the United States of America requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Acacia believes that, of the significant accounting policies described herein, the accounting policies associated with revenue recognition, the valuation of the equity instruments discussed at Notes 6, 14 and 17, the valuation of Series A redeemable convertible preferred stock, Series A warrants, Series B warrants, and embedded derivatives, stock-based compensation expense, impairment of patent-related intangible assets, the determination of the economic useful life of amortizable intangible assets, income taxes and valuation allowances against net deferred tax assets, require its most difficult, subjective or complex judgments.

Income Per Share. For periods in which the Company generates net income, the Company computes basic net income per share attributable to common stockholders using the two-class method required for capital structures that include participating securities. Under the two-class method, securities that participate in non-forfeitable dividends, such as the Company’s outstanding unvested restricted stock and Series A Redeemable Convertible Preferred Stock, are considered participating securities and are allocated a portion of the Company’s earnings. For periods in which the Company generates a net loss, net losses are not allocated to holders of the Company’s participating securities as the security holders are not contractually obligated to share in the Company’s losses.

Basic net income (loss) per share of common stock is computed by dividing net (income) loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per share of common stock is computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common and dilutive common equivalent shares outstanding for the period using the treasury stock method or the as-converted method, or the two-class method for participating securities, whichever is more dilutive. Potentially dilutive common stock equivalents consist of stock options, restricted stock units, unvested restricted stock, Series A Redeemable Convertible Preferred Stock, Series A Warrants, and Series B Warrants.

The following table presents the calculation of basic and diluted income per share of common stock:

	Years Ended
	December 31,
	2020			2019
	(In thousands, except share and per share information)
Numerator:
Net income (loss) attributable to Acacia Research Corporation	$	113,444		$	(17,115	)
Dividend on Series A redeemable convertible preferred stock		(1,381	)		–
Accretion of Series A redeemable convertible preferred stock		(2,835	)		(307	)
Undistributed earnings allocated to participating securities		(18,898	)		–
Net income (loss) attributable to common stockholders - basic		90,330			(17,422	)
Add: Accretion of Series A redeemable convertible preferred stock		–			307
Less: Change in fair value of Series A redeemable convertible preferred stock embedded derivative		–			(3,258	)
Less: Change in fair value of Series A warrants		(1,348	)		–
Less: Change in fair value of dilutive Series B warrants		(5,557	)		–
Add: Interest expense associated with Starboard Notes, net of tax		1,889			–
Add: Undistributed earnings allocated to participating securities		18,898			–
Reallocation of undistributed earnings to participating securities		(15,740	)		–
Net income (loss) attributable to common stockholders - diluted	$	88,471		$	(20,373	)
Denominator:
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders - basic		48,840,829			49,764,002
Potentially dilutive common shares:
Series A Preferred Stock		–			1,132,771
Restricted stock units		637,044			–
Employee stock options		2,952			–
Series A Warrants		77,592			–
Series B Warrants		7,876,712			–
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders - diluted		57,435,128			50,896,773
Basic net income (loss) per common share	$	1.85		$	(0.35	)
Diluted net income (loss) per common share	$	1.54		$	(0.40	)

Anti-dilutive potential common shares excluded from the computation of diluted net income (loss) per common share:
Equity-based incentive awards	206,916	1,783,254
Series A warrants	–	5,000,000
Series B warrants	68,493,151	–
Total	68,700,067	6,783,254

Treasury Stock. Repurchases of the Company’s outstanding common stock are accounted for using the cost method. The applicable par value is deducted from the appropriate capital stock account on the formal or constructive retirement of treasury stock. Any excess of the cost of treasury stock over its par value is charged to additional paid-in capital, and reflected as Treasury Stock on the consolidated balance sheets.