Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (140,848)	$ (84,553)	$ 67,975
Stock-based compensation	76,673	43,383	12,393
Depreciation and amortization	8,267	5,942	4,439
Amortization/(accretion) of note premiums	266	525	1,069
Changes in operating assets and liabilities:
Accounts receivable	(9,409)	(184)	(334)
Prepaid expenses and other current assets	(360)	(387)	(3,711)
Accounts payable	2,628	(821)	4,844
Accrued expenses	9,522	1,989	2,450
Deferred revenue	223,258	(63,514)	82,804
Other	1,227	2,229	1,106
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	171,224	(95,391)	173,035
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(23,567)	(11,952)	(12,001)
Purchases of investments	(240,703)	(278,964)	(90,266)
Proceeds from sale of investments	122,592	50,138	54,521
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(141,678)	(240,778)	(47,746)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on notes payable			(2,415)
Proceeds from the exercises of stock options	11,305	7,469	8,275
Proceeds from the issuance of common stock		250,479	60,522
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	11,305	257,948	66,382
NET INCREASE (DECREASE) IN CASH	40,851	(78,221)	191,671
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	143,583	221,804	30,133
CASH AND CASH EQUIVALENTS AT END OF PERIOD	184,434	143,583	221,804
Supplementary disclosures:
Interest paid			(27)
Income Taxes (Paid)/Refunded	$ (2)	$ 103	$ (302)