Note 3 - Short-term Investments

6 Months Ended

Mar. 31, 2024

Notes to Financial Statements

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

3. 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. 

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

	As of March 31, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Short-term investments:
Corporate bonds	$	21,937	$	—	$	(14	)	$	21,923
U.S. treasury securities and securities of U.S. government-sponsored agency		8,526		—		(1	)		8,525
Total	$	30,463	$	—	$	(15	)	$	30,448

	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

The Company had no securities in a material unrealized loss position at  March 31, 2024 and  September 30, 2023 and does not believe these securities represent credit losses based on the evaluation of evidence, which includes an assessment of whether it is more likely than not it will be required to sell or intend to sell the investment before recovery of the investments amortized cost basis. No gains or losses were realized during the six months ended March 31, 2024 and 2023 from the sale of short-term investments.