5.Cash and Cash Equivalents and Short-Term Investments

The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Short-term investments include investments with maturities greater than three months, but not exceeding 12 months, or highly liquid investments with maturities greater than 12 months that the Company intends to liquidate during the next 12 months for working capital needs.

The following tables summarize the Company's short-term investments at December 31, 2020:


			Estimated		Carrying
December 31, 2020	Cost		Fair Value		Value
		(in thousands)
Investments:
Short-term:
Trading securities	$	59	$	79	$	79
Total trading securities		59		79		79
Total short term	$	59	$	79	$	79

The short-term investments at December 31, 2020, consist of 1,000,000 common shares of Fabled Silver Gold Corp., formerly known as Fabled Copper Corp. (“Fabled”), a junior mining company that entered into an option agreement with the Company to acquire the Company’s option to earn a 100% interest in the Santa Maria mining claims located in Chihuahua, Mexico (see Note 9). The 1,000,000 common shares were issued to the Company as partial consideration per the terms of the option agreement.

The Company previously owned 7,500,000 common shares of Golden Tag Resources, Ltd. (“Golden Tag”), a junior mining company that was a joint venture partner in the Company’s previously owned San Diego exploration property in Mexico. All the Golden Tag shares were sold during the third quarter 2019, resulting in net proceeds of approximately $113,000. For the year ended December 31, 2019 the Company recorded total losses related to ownership of the Golden Tag shares of approximately $217,000 recorded in “Interest and other income (expense), net” in the accompanying Consolidated Statements of Operations. The Company had no short-term investments at December 31, 2019.

Credit Risk

The Company invests substantially all of its excess cash with high credit-quality financial institutions or in U.S. government or debt securities. Credit risk is the risk that a third party might fail to fulfill its performance obligations under the terms of a financial instrument. For cash and equivalents and investments, credit risk represents the carrying amount on the balance sheet. The Company mitigates credit risk for cash and equivalents and investments by placing its funds and investments with high credit-quality financial institutions, limiting the amount of exposure to each of the financial institutions, monitoring the financial condition of the financial institutions and investing only in government and corporate securities rated “investment grade” or better. The Company invests with financial institutions that maintain a net worth of not less than $1 billion and are members in good standing of the Securities Investor Protection Corporation.