Condensed Consolidated Income Statements - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Sales of physical commodities	$ 13,918.9	$ 8,883.5
Principal gains, net	251.1	203.4
Revenue from contract with customer	920.7	255.5
Interest income	31.0	21.2
Total revenues	14,341.4	9,250.5
Cost of sales of physical commodities	13,890.9	8,870.4
Operating revenues	450.5	380.1
Transaction-based clearing expenses	70.9	65.4
Introducing broker commissions	38.3	38.2
Interest expense	15.7	9.9
Interest expense on corporate funding	11.8	10.5
Net operating revenues	313.8	256.1
Compensation and other expenses:
Compensation and benefits	175.0	153.6
Trading systems and market information	16.1	13.7
Professional fees	11.9	9.3
Non-trading technology and support	13.0	10.9
Occupancy and equipment rental	8.7	8.6
Selling and marketing	11.0	8.8
Travel and business development	2.9	1.0
Communications	1.9	2.3
Depreciation and amortization	9.1	8.4
Bad debt (recoveries) expense, net	(0.2)	1.5
Other	11.9	11.1
Total compensation and other expenses	261.3	229.2
Income before tax	52.5	26.9
Income tax expense	10.8	7.4
Net income	$ 41.7	$ 19.5
Earnings per share:
Basic (in dollar per shares)	$ 2.09	$ 1.00
Diluted (in dollar per shares)	$ 2.04	$ 0.98
Weighted-average number of common shares outstanding:
Basic (in shares)	19,383,303	18,940,876
Diluted (in shares)	19,858,712	19,470,853
Commission and clearing fees
Revenues:
Revenue from contract with customer	$ 116.3	$ 119.4
Consulting, management, and account fees
Revenues:
Revenue from contract with customer	$ 24.1	$ 23.0