Marketable Securities

3 Months Ended

Dec. 31, 2020

9. Marketable Securities

We did not hold any marketable securities as of December 31, 2020. In December 2020, we sold our remaining marketable securities to partially fund the Arena acquisition, resulting in proceeds of $56.2 million. Neither gross realized gains nor gross realized losses related to the sale were material. The amortized cost and fair value of marketable securities as of September 30, 2020 were as follows:

(in thousands)

September 30, 2020

Amortized

cost

Gross

unrealized

gains

Gross

unrealized

losses

Fair value

Corporate notes/bonds

58,793

323

(17

)

59,099

The following table summarizes the fair value and gross unrealized losses aggregated by category and the length of time that individual securities had been in a continuous unrealized loss position as of September 30, 2020:

(in thousands)	September 30, 2020
	Less than twelve months					Greater than twelve months				Total
	Fair Value		Gross unrealized loss			Fair Value		Gross unrealized loss		Fair Value		Gross unrealized loss
Corporate notes/bonds	$	9,841	$	(17	)	$	—	$	—	$	9,841	$	(17	)

The following table presents our marketable securities by contractual maturity date as of September 30, 2020:

(in thousands)	September 30, 2020
	Amortized cost		Fair value
Due in one year or less	$	27,727	$	27,899
Due after one year through three years		31,066		31,200
Total	$	58,793	$	59,099