Note 3 - Investments

12 Months Ended

Sep. 30, 2023

Notes to Financial Statements

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

3. Investments

Short-term Investments

The Company classifies its short-term investments as available-for-sale securities. Available-for-sale securities are carried at fair market value with net unrealized gains and losses reported as a component of accumulated other comprehensive loss in stockholders’ equity. No gains or losses were realized from the sale of short-term investments for the fiscal year ended September 30, 2023.  The Company realized losses of $22,000 from the sale of short-term investments for the fiscal year ended September 30, 2022.

The Company’s short-term investments were composed of the following (in thousands):

	AS OF SEPTEMBER 30, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments:
Corporate bonds	$	11,310	$	—	$	(15	)	$	11,295
U.S. treasury securities and securities of U.S. government-sponsored agency		3,622		4		—			3,626
Total	$	14,932	$	4	$	(15	)	$	14,921

	AS OF SEPTEMBER 30, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments:
Corporate bonds	$	909	$	—	$	(15	)	$	894
Total	$	909	$	—	$	(15	)	$	894

The Company’s short-term investments have contractual maturities ranging from January 2024 to September 2024.