Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Schedule of assets and liabilities subject to fair value measurements

Assets and liabilities subject to fair value measurements are as follows (in millions):


	As of December 31, 2021
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds(1)	$	516.7	$	—	$	—	$	516.7

U.S. government and agency securities(2)	—		2,173.6		—		2,173.6
Corporate debt securities(2)	—		481.1		—		481.1
Equity securities(3)	70.4		—		—		70.4
Contingent consideration(4)	—		—		1.2		1.2
Total assets	$	587.1	$	2,654.7	$	1.2	$	3,243.0
Liabilities
Contingent consideration(5)	—		—		20.8		20.8
Total liabilities	$	—	$	—	$	20.8	$	20.8


	As of December 31, 2020
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds(1)	$	323.1	$	—	$	—	$	323.1

U.S. government and agency securities(2)	—		1,912.1		—		1,912.1
Corporate debt securities(2)	—		334.4		—		334.4
Equity securities(3)	78.4		—		—		78.4
Contingent consideration(4)	—		—		4.1		4.1
Total assets	$	401.5	$	2,246.5	$	4.1	$	2,652.1
Liabilities
Contingent consideration(5)	—		—		17.1		17.1
Total liabilities	$	—	$	—	$	17.1	$	17.1

(1)Included in cash and cash equivalents in our consolidated balance sheets.

(2)Included in cash and cash equivalents and current and non-current marketable investments in our consolidated balance sheets. Refer to Note 4—Investments—Marketable Investments—Available-for-Sale Debt Securities for further information. The fair value of these securities is principally measured or corroborated by trade data for identical securities for which related trading activity is not sufficiently frequent to be considered a Level 1 input or comparable securities that are more actively traded.

(3)Included in current marketable investments in our consolidated balance sheets. The fair value of these securities is based on quoted market prices for identical instruments in active markets. During the years ended December 31, 2021 and 2020, we recognized $50.8 million and $25.1 million of net unrealized and realized gains, respectively, on these securities. We recorded these gains and losses in our consolidated statements of operations within other income, net. Refer to Note 4—Investments—Marketable Investments—Investments in Equity Securities with Readily Determinable Fair Values.

(4)Included in other non-current assets in our consolidated balance sheet as of December 31, 2021 and in other currents assets and other non-current assets in our consolidated balance sheet as of December 31, 2020. We estimated the fair value of contingent consideration using a Monte Carlo simulation. The Monte Carlo simulation incorporates Level 3 inputs including price volatility of peer company stocks and the probability of completing certain milestones during a specified period of time. The fair value of our contingent consideration assets decreased by $2.9 million from December 31, 2020 to December 31, 2021. The loss was recorded within other income, net in our consolidated statements of operations.

(5)Included in other non-current liabilities in our consolidated balance sheets. The fair value of our contingent consideration obligations has been estimated using probability-weighted discounted cash flow models (DCFs). The DCFs incorporate Level 3 inputs including estimated discount rates that we believe that market participants would consider relevant in pricing and the projected timing and amount of cash flows, which are estimated and developed, in part, based on the requirements specific to each acquisition agreement. The fair value of our contingent consideration liabilities increased by $3.7 million from December 31, 2020 to December 31, 2021. The loss was recorded within research and development in our consolidated statements of operations.