The following table shows the Company’s cash, available-for-sale securities, and short-term and long-term investment securities by major security type as of December 31, 2018 and 2017:



	December 31, 2018
				Gross		Gross
	Level			Unrealized		Unrealized
	⁽¹⁾	Fair Value		Holding Gains		Holding Losses			Adjusted Cost
Cash and Cash Equivalents
Cash		$	1,048,272	$	—	$	—		$	1,048,272
Money Market Funds	1	1,338,042							1,338,042
Subtotal		2,386,314		—		—			2,386,314
Short-Term Investment Securities ⁽²⁾
Corporate Bonds ⁽⁴⁾	2	38,731,120		—		(85,321		)	38,816,441
Long-Term Investment Securities ⁽³⁾
Corporate Bonds	2	—		—		—			—
Total		$	41,117,434	$	—	$	(85,321	)	$	41,202,755



	December 31, 2017
				Gross		Gross
	Level			Unrealized		Unrealized
	⁽¹⁾	Fair Value		Holding Gains		Holding Losses			Adjusted Cost
Cash and Cash Equivalents
Cash		$	838,110	$	—	$	—		$	838,110
Money Market Funds	1	4,948,238		—		—			4,948,238
Subtotal		5,786,348		—		—			5,786,348
Short-Term Investment Securities ⁽²⁾
Corporate Bonds ⁽⁴⁾	2	41,811,273		—		(87,481		)	41,898,754
Long-Term Investment Securities ⁽³⁾
Corporate Bonds ⁽⁴⁾	2	911,698		—		(10,950		)	922,648
Total		$	48,509,319	$	—	$	(98,431	)	$	48,607,750

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Notes:

(1) Definition of the three-level fair value hierarchy:


•	Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities


•	Level 2 - Other inputs that are directly or indirectly observable in the markets


•	Level 3 - Inputs that are generally unobservable

(2) Short-term investment securities will mature within 12 months or less, from the applicable reporting date.

(3) Long-term investment securities will mature between 12 and 18 months, from the applicable reporting date.

(4) The premium paid to purchase held-to-maturity investment securities was $378,681 and $915,084 for the years ended December 31, 2018 and 2017, respectively.