Cash Equivalents and Equity Securities

Cash equivalents and equity securities at December 31, 2018 and 2017 consisted of the following (in thousands):



	December 31, 2018
	Adjusted Cost		Gross Unrealized Gains ⁽³⁾		Gross Unrealized Losses (3)		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds ⁽¹⁾	$	31,225	$	—	$	—	$	31,225	n/a
Common shares of CO₂ Solutions ⁽²⁾	563		25		—		588		n/a
Total	$	31,788	$	25	$	—	$	31,813



	December 31, 2017
	Adjusted Cost		Gross Unrealized Gains (3)		Gross Unrealized Losses (3)		Estimated Fair Value		Average Contractual Maturities
									(in days)
Money market funds ⁽¹⁾	$	6,778	$	—	$	—	$	6,778	n/a
Common shares of CO₂ Solutions ⁽²⁾	563		108		—		671		n/a
Total	$	7,341	$	108	$	—	$	7,449

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

⁽²⁾Common shares of CO₂ Solutions are classified in equity securities on our 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 the consolidated statements of operations. Prior to 2018 gross unrealized gains and gross unrealized losses related to our investment in CO₂ Solutions were recorded in accumulated other comprehensive loss on the balance sheet.

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. As of December 31, 2017, the total cash and cash equivalents balance of $31.2 million was comprised of money market funds of $6.8 million and cash of $24.4 million held with major financial institutions worldwide.

In December 2009, we purchased 10,000,000 common shares of CO₂ Solutions, 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 December 31, 2018, 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.

In 2018, we recognized an unrealized loss of $84 thousand related to our investment in CO₂ Solutions in other expense, in the consolidated statements of operations.