Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (77,474)	$ (36,120)
Stock-based compensation	42,051	27,510
Depreciation and amortization	5,763	4,168
Amortization/(accretion) of note premiums/discounts	142	653
Changes in operating assets and liabilities:
Accounts receivable	174	(21,031)
Prepaid expenses and other current assets	(2,895)	(863)
Deferred revenue	211,392	(56,530)
Accounts payable	3,208	(3,576)
Accrued expenses	13,682	(54)
Other	(702)	1,302
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	195,341	(84,541)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(15,368)	(10,067)
Purchases of investments	(95,195)	(193,964)
Proceeds from sale of investments	87,130	29,148
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(23,433)	(174,883)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the exercises of stock options	10,490	6,464
Proceeds from the issuance of common stock		250,479
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	10,490	256,943
NET INCREASE (DECREASE) IN CASH	182,398	(2,481)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	143,583	221,804
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 325,981	$ 219,323