Consolidated Balance Sheets - USD ($)	Sep. 30, 2020	Sep. 30, 2019
CURRENT ASSETS
Cash and cash equivalents	$ 143,582,667	$ 221,804,128
Accounts receivable	845,673	661,361
Prepaid expenses	4,250,896	3,317,999
Other current assets	1,781,691	2,563,435
Marketable securities	85,019,719
Short term investments	86,889,751	36,899,894
TOTAL CURRENT ASSETS	322,370,397	265,246,817
Property and equipment, net	30,880,868	23,214,899
Intangible assets, net	15,363,151	17,063,580
Long term investments	137,486,883	44,175,993
Right-of-use assets	16,137,085
Other assets	265,359	144,148
TOTAL ASSETS	522,503,743	349,845,437
CURRENT LIABILITIES
Accounts payable	6,828,909	7,649,921
Accrued expenses	5,388,556	6,504,729
Accrued payroll and benefits	8,060,854	4,955,887
Lease liabilities	1,094,777
Deferred rent		173,952
Deferred revenue	19,291,075	77,769,629
Other current liabilities	17,262	16,561
TOTAL CURRENT LIABILITIES	40,681,433	97,070,679
LONG-TERM LIABILITIES
Lease liabilities, net of current portion	20,043,178
Deferred rent, net of current portion		3,703,364
Deferred revenue, net of current portion		5,035,142
TOTAL LONG-TERM LIABILITIES	20,043,178	8,738,506
Commitments and contingencies (Note 7)
Arrowhead Pharmaceuticals, Inc. stockholders' equity:
Common stock, $0.001 par value; 145,000,000 shares authorized; 102,376,303 and 95,506,271 shares issued and outstanding as of September 30, 2020 and September 30, 2019, respectively	194,746	187,876
Additional paid-in capital	965,410,146	664,086,155
Accumulated other comprehensive income (loss)	18,433	(391,624)
Accumulated deficit	(503,844,193)	(419,290,967)
Total Arrowhead Pharmaceuticals, Inc. stockholders' equity	461,779,132	244,591,440
Noncontrolling interest		(555,188)
TOTAL STOCKHOLDERS’ EQUITY	461,779,132	244,036,252
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 522,503,743	$ 349,845,437