Cash Equivalents and Marketable Securities

Cash equivalents and marketable securities at March 31, 2019 and at December 31, 2018 consisted of the following (in thousands):



	March 31, 2019
	Adjusted Cost		Gross Unrealized Gains ⁽³⁾		Gross Unrealized Losses⁽³⁾			Estimated Fair Value
Money market funds⁽¹⁾	$	28,001	$	—	$	—		$	28,001
Common shares of CO₂Solutions ⁽²⁾	563		—		(79		)	484
Total	$	28,564	$	—	$	(79	)	$	28,485



	December 31, 2018
	Adjusted Cost		Gross Unrealized Gains⁽³⁾		Gross Unrealized Losses⁽³⁾		Estimated Fair Value
Money market funds ⁽¹⁾	$	31,225	$	—	$	—	$	31,225
Common shares of CO₂Solutions⁽²⁾	563		25		—		588
Total	$	31,788	$	25	$	—	$	31,813

⁽¹⁾Money market funds are classified in cash and cash equivalents on our unaudited condensed consolidated balance sheets.

⁽²⁾ Common shares of CO₂Solutions are classified in equity securities on our unaudited condensed consolidated balance sheets.

⁽³⁾As a result of adopting ASU 2016-01, in 2018 and thereafter gross unrealized gains and gross unrealized losses related to our investment in CO₂ Solutions were recognized in other expense, in our unaudited condensed consolidated statements of operations.

As of March 31, 2019, the total cash and cash equivalents balance of $47.3 million was comprised of money market funds of $28.0 million and cash of $19.3 million held with major financial institutions worldwide. As of December 31, 2018, the total cash and cash equivalents balance of $53.0 million was comprised of money market funds of $31.2 million and cash of $21.8 million held with major financial institutions worldwide.

In December 2009, we purchased 10,000,000 common shares of CO₂Solutions, a company based in Quebec, Canada, whose shares are publicly traded in Canada on TSX Venture Exchange. Our purchase represented approximately 16.6% of CO₂ Solutions’ total common shares outstanding at the time of investment and was made in a private placement subject to a four-month statutory resale restriction. This restriction expired on April 15, 2010. Our investment in CO₂ Solutions is recorded at its fair value. See Note 7, “Fair Value Measurements.” Through March 31, 2019, we concluded that we did not have the ability to exercise significant influence over CO₂ Solutions’ operating and financial policies.

On January 1, 2018, we adopted ASU 2016-01. Upon adoption, we reclassified the $0.5 million net unrealized loss from accumulated other comprehensive loss to our opening accumulated deficit. As of March 31, 2019, we recognized an unrealized loss of $0.1 million related to our investment in CO₂ Solutions in other expense, in the unaudited condensed consolidated statements of operations.