Note 2 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2025

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value Measured as of September 30, 2025 Using:
	Adjusted Cost		Unrealized Gains (Losses)			Fair Value		Cash and Cash Equivalent		Marketable Securities
Assets
Level 1
Money market funds	$	42,531	$	—		$	42,531	$	42,531	$	—
Level 2
Asset-backed securities		4,986		1			4,987		—	$	4,987
Corporate bonds		19,380		(2	)		19,378		—		19,378
Commercial paper		7,453		(2	)		7,451		—		7,451
U.S. Government securities		9,483		(1	)		9,482		—		9,482
Total financial assets	$	83,833	$	(4	)	$	83,829	$	42,531	$	41,298
Liabilities
Level 2
Private placement warrant liability	$	—	$	—		$	1	$	—	$	—
Level 3
Convertible note, current		—		—			106		—		—
Derivative warrant liabilities		—		—			787		—		—
Total financial liabilities	$	—	$	—		$	894	$	—	$	—

	Fair Value Measured as of December 31, 2024 Using:
	Adjusted Cost		Unrealized Gains		Fair Value		Cash and Cash Equivalent		Marketable Securities
Assets
Level 1
Money market funds	$	6,965	$	—	$	6,965	$	6,965	$	—
Level 2
Corporate bonds		9,660		4		9,664		—		9,664
Commercial paper		945		—		945		—		945
U.S. Government securities		1,402		1		1,403		—		1,403
Total financial assets	$	18,972	$	5	$	18,977	$	6,965	$	12,012
Liabilities
Level 2
Private placement warrant liability	$	—	$	—	$	—	$	—	$	—
Level 3
Derivative warrant liability		—		—		26		—		—
Total financial liabilities	$	—	$	—	$	26	$	—	$	—

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Derivative Warrant Liabilities			2025 Note			Total
Balance at December 31, 2024	$	26		$	—		$	26
Additions		1,945			3,266			5,211
Change in fair value included in other income (expense), net		1,809			314			2,123
Payments and conversions		—			(3,474	)		(3,474	)
Extinguishment and exercise		(2,992	)		—			(2,992	)
Balance at September 30, 2025	$	788		$	106		$	894

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

	July 28, 2025
Expected term (years)		3.9
Expected volatility		144.3	%
Risk-free interest rate		3.9	%
Dividend yield		—	%
Exercise price	$	2.22

	September 30, 2025
Expected term (years)		4.9
Expected volatility		143.0	%
Risk-free interest rate		3.7	%
Dividend yield		—	%
Exercise price	$	2.22