Note 4 - Short-term Investments

12 Months Ended

Sep. 30, 2024

Notes to Financial Statements

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

4. Short-term Investments

The Company classifies its short-term investments as available-for-sale debt securities. These 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 SEPTEMBER 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
Short-term investments:
Corporate bonds	$	21,814	$	35	$	—	$	21,849
U.S. treasury securities and securities of U.S. government-sponsored agency		8,356		22		—		8,378
Total	$	30,170	$	57	$	—	$	30,227

	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

At September 30, 2024 and 2023, accrued interest receivable related to these investments of $0.3 million and $0.1 million, respectively, are included as a component of prepaid expenses and other current assets.

The Company has no debt securities in a material unrealized loss position at September 30, 2024 and 2023 and does not believe the unrealized losses associated with these debt 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 from the sale of short-term investments for the fiscal years ended September 30, 2024 and 2023. 

The Company’s short-term investments have contractual maturities ranging from October 2024 to September 2025.