Description of Business and Significant Accounting Policies (Policies)	12 Months Ended
Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of StoneX Group Inc. and all other entities in which the Company has a controlling financial interest. All material intercompany transactions and balances have been eliminated in consolidation. Unless otherwise stated herein, all references to fiscal 2020, fiscal 2019, and fiscal 2018 refer to the Company’s fiscal years ended September 30. In the consolidated income statements, the total revenues reported combine gross revenues for the physical commodities business and net revenues for all other businesses. The subtotal ‘operating revenues’ in the consolidated income statements is calculated by deducting physical commodities cost of sales from total revenues. The subtotal ‘net operating revenues’ in the consolidated income statements is calculated as operating revenues less transaction-based clearing expenses, introducing broker commissions and interest expense. Transaction-based clearing expenses represent variable expenses paid to executing brokers, exchanges, clearing organizations and banks in relation to transactional volumes. Introducing broker commissions include commission paid to non-employee third parties that have introduced clients to the Company. Net operating revenues represent revenues available to pay variable compensation to risk management consultants and traders and direct non-variable expenses, as well as variable and non-variable expenses of operational and administrative employees.
Consolidation	The accompanying consolidated financial statements include the accounts of StoneX Group Inc. and all other entities in which the Company has a controlling financial interest. All material intercompany transactions and balances have been eliminated in consolidation.
Fiscal Period	Unless otherwise stated herein, all references to fiscal 2020, fiscal 2019, and fiscal 2018 refer to the Company’s fiscal years ended September 30.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates and assumptions relate to fair value measurements for financial instruments, revenue recognition, the provision for probable losses from bad debts, valuation of inventories, and incomes taxes and contingencies. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. The Company reviews all significant estimates affecting the financial statements on a recurring basis and records the effect of any necessary adjustments prior to their issuance. Although these and other estimates and assumptions are based on the best available information, actual results could be materially different from these estimates.
Reclassifications	Reclassifications During the year ended September 30, 2020, the Company reclassified certain selling and marketing related costs in connection with the acquisition of Gain Capital Holdings, Inc. (“Gain”). In performing this reclassification, the Company has made retrospective adjustments to the consolidated income statements for the years ended September 30, 2019 and 2018. For the years ended September 30, 2019 and 2018, selling and marketing related costs of $5.2 million and $6.2 million, were reclassified from ‘Other’ expense to ‘Selling and marketing’ expense. During the year ended September 30, 2019, the Company reclassified certain brokerage related revenues for which the Company earns commissions on trading activity in the capacity of an agent. In performing this reclassification, the Company has made a retrospective adjustment to the consolidated income statement for the year ended September 30, 2018. For the year ended September 30, 2018, brokerage related revenue of $35.0 million, was reclassified from ‘principal gains, net’ to ‘commissions and clearing fees’. Additionally, the Company has changed the name of the line item ‘trading gains, net’ to ‘principal gains, net’ on the consolidated income statement in order to reflect the fact that these revenue streams are earned from trading financial instruments in the capacity of a principal and in order to properly segregate revenues earned from contracts with clients.
Foreign Currency Translation	Foreign Currency Translation The Company’s consolidated financial statements are reported in U.S. dollars. The Company’s foreign subsidiaries maintain their records either in U.S. dollars or in certain instances the currency of the country in which they operate. The method of translating local currency financial information into U.S. dollars depends on whether the economy in which the foreign subsidiary operates has been designated as highly inflationary or not. Economies with a three-year cumulative inflation rate of more than 100% are considered highly inflationary. Assets and liabilities of foreign subsidiaries in non-highly inflationary economies are translated into U.S. dollars using rates of exchange at the balance sheet date. Translation adjustments are recorded in other comprehensive income (loss). Revenues and expense are translated at rates of exchange in effect during the year. Transaction gains and losses are recorded in earnings. Foreign subsidiaries that operate in highly inflationary countries use the U.S. dollar as their functional currency. Local currency monetary assets and liabilities are remeasured into U.S. dollars using rates of exchange as of each balance sheet date, with remeasurement adjustments and other transaction gains and losses recognized in earnings. Nonmonetary assets and liabilities do not fluctuate with changes in the local currency exchange rates to the dollar as the translated amounts for nonmonetary assets and liabilities at the end of the accounting period in which the economy becomes highly inflationary becomes the accounting basis for those assets and liabilities in the period of change and subsequent periods. Revenues and expenses are translated at rates of exchange in effect during the year. The Company operates asset management and debt trading businesses in Argentina through various wholly-owned subsidiaries. Operating revenues from the Argentinean subsidiaries represented approximately 2% of the consolidated operating revenues for the year ended September 30, 2020. The operating environment in Argentina continues to present business challenges, including ongoing devaluation of the Argentine peso and significant inflation. For the year ended September 30, 2018, the Argentine peso declined approximately 139% (from 17.3 to 41.3 pesos to the U.S. dollar). Based upon inflationary data published by the International Practices Task Force of the Center for Audit Quality, the economy of Argentina became highly inflationary during the three months ended June 30, 2018. Beginning July 1, 2018, the Company designated Argentina’s economy as highly inflationary for accounting purposes. As a result, the Company has accounted for the Argentinean entities using the U.S. dollar as their functional currency beginning in the quarter ending September 30, 2018. Argentine peso-denominated monetary assets and liabilities are remeasured at each balance sheet date to the currency exchange rate then in effect, with currency remeasurement gains and loses recognized in earnings. The translated balances for nonmonetary assets and liabilities as of June 30, 2018, became the accounting basis for those assets in the period of change and subsequent periods
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers cash held at banks and all highly liquid investments not held for trading purposes, with original or acquired maturities of 90 days or less, including certificates of deposit and money market mutual funds, to be cash and cash equivalents. Cash and cash equivalents consists of cash, certificates of deposit, and money market mutual funds not deposited with or pledged to clearing organizations, broker-dealers, clearing organizations or counterparties, or segregated under federal or other regulations. Certificates of deposit are stated at cost plus accrued interest, which approximates fair value, and may be withdrawn at any time at the discretion of the Company without penalty. Money market mutual funds are stated at their net asset value.
Cash, Securities and Other Assets Segregated under Federal and other Regulations	Cash, Securities and Other Assets Segregated under Federal and other Regulations Pursuant to requirements of the Commodity Exchange Act and Commission Regulation 30.7 of the U.S. Commodity Futures Trading Commission (“CFTC”) in the U.S., the Markets in Financial Instruments Implementing Directive 2006/73/EC underpinning the Client Asset (“CASS”) rules in the Financial Services Authority (“FSA”) handbook in the United Kingdom (“U.K.”), and the Securities & Futures Act (“SFA”) in Singapore, funds deposited by clients relating to futures and options on futures contracts in regulated commodities must be carried in separate accounts which are designated as segregated or secured client accounts. Additionally, in accordance with Rule 15c3-3 of the Securities Exchange Act of 1934 (“Rule 15c3-3”), the Company maintains separate accounts for the exclusive benefit of securities clients and proprietary accounts of broker dealers (“PABs”). Rule 15c3-3 requires the Company to maintain special reserve bank accounts (“SRBAs”) for the exclusive benefit of securities clients and PABs. The deposits in segregated client accounts and SRBAs are not commingled with the funds of the Company. Under the FSA’s rules, certain categories of clients may choose to opt-out of segregation.
Collateralized Transactions	Collateralized Transactions The Company enters into securities purchased under agreements to resell, securities sold under agreements to repurchase, securities borrowed transactions, and securities loaned transactions primarily to fund principal debt trading, acquire securities to cover short positions, acquire securities for settlement, or meet counterparty needs under matched-booked trading strategies. These transactions are accounted for as collateralized financing transactions and are recorded at their contractual amounts plus accrued interest. In connection with these agreements and transactions, it is the policy of the Company to receive or pledge cash or securities to collateralize such agreements and transactions in accordance with contractual arrangements. The Company monitors the fair value of the collateral on a daily basis and the Company may require counterparties, or may be required by counterparties, to deposit additional collateral or return collateral pledged. Interest income and interest expense are recognized over the life of the arrangements and are recorded in the statement of income as interest income or interest expense, as applicable. The carrying amount of these transactions approximate fair value due to their short-term nature and the level of collateralization. These transactions are reported gross, except when a right of offset exists and the other criteria for netting under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 210-20, Balance Sheet - Offsetting are met.
Deposits with and Receivables from Broker-dealers, Clearing Organizations and Counterparties, and Payables to Broker-dealers, Clearing Organizations and Counterparties	Deposits with and Receivables from Broker-dealers, Clearing Organizations and Counterparties, and Payables to Broker-dealers, Clearing Organizations and Counterparties As required by regulations of the CFTC, FSA, and Monetary Authority of Singapore (“MAS”), client funds received to margin, guarantee, and/or secure commodity futures and futures on options as well as retail foreign exchange transactions are segregated and accounted for separately from the general assets of the Company. Deposits with broker-dealers, clearing organizations, and counterparties pertain primarily to deposits made to satisfy margin requirements on client and proprietary open futures and options on futures positions and to satisfy the requirements set by clearing exchanges for clearing membership. The Company also pledges margin deposits with various counterparties for over-the-counter (“OTC”) derivative contracts, and these deposits are also included in deposits with broker-dealers, clearing organizations, and counterparties. The Company also deposits cash margin with various securities clearing organizations as an ongoing condition of the securities clearing relationships, and these deposits are also included in deposits with broker-dealers, clearing organizations, and counterparties. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties are reported gross, except where a right of offset exists. As of September 30, 2020 and September 30, 2019, the Company had cash and cash equivalents on deposit with or pledged to broker-dealers, clearing organizations, and counterparties of approximately 1.6 billion. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also includes guaranty deposits with clearing exchanges. The guaranty deposits are held by the clearing exchanges for use in potential default situations by one or more members of the clearing exchanges. The guaranty deposits may be applied to the Company’s obligations to the clearing exchange, or to the clearing exchange’s obligations to unrelated parties. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also include securities pledged to clearing exchanges. These securities are either pledged to the Company by its clients or represent investments of client funds. It is the Company’s practice to include client-owned securities on its consolidated balance sheets, as the rights to those securities have been transferred to the Company under the terms of the futures trading agreements. Securities pledged primarily include U.S. Treasury obligations, foreign government obligations, and certain exchange-traded funds (“ETFs”). Securities that are not client-owned, and represent an investment of client funds, are adjusted to fair value with associated changes in unrealized gains or losses recorded in ‘interest income’ in the consolidated income statements. For client-owned securities, the change in fair value is offset against the payable to clients with no impact recognized in the consolidated income statements. The fair value of these securities included within deposits with and receivables from broker-dealers, clearing organizations, and counterparties was $1,949.3 million and $603.8 million as of September 30, 2020 and September 30, 2019, respectively. Management has considered guidance required by ASC 860, Transfers and Servicing as it relates to securities pledged by clients to margin their futures and options on futures trading accounts. Based on a review of the agreements with the client, management believes the transferor surrenders control over those assets because: (a) the transferred assets have been isolated from the transferor—put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership, (b) each transferee has the right to pledge or exchange the assets (or beneficial interests) it received, and no condition both constrains the transferee (or holder) from taking advantage of its right to pledge or exchange and provides more than a trivial benefit to the transferor and (c) the transferor does not maintain effective control over the transferred assets through either (1) an agreement that both entitles and obligates the transferor to repurchase or redeem them before their maturity or (2) the ability to unilaterally cause the holder to return specific assets, other than through a cleanup call. Under this guidance, the Company reflects the client collateral assets and corresponding liabilities in the Company’s consolidated balance sheets as of September 30, 2020 and September 30, 2019. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also includes amounts due from clearing exchanges for unrealized gains and losses associated with clients’ options on futures contracts. See discussion in the Financial Instruments section below for additional information on the Company’s accounting policies for derivative contracts. For client-owned derivative contracts, the fair value is offset against the payable to clients with no impact recognized on the consolidated income statements. The Company maintains client omnibus and proprietary accounts with other clearing organizations, and the equity balances in those accounts along with any margin cash or securities deposited with the clearing organizations are included in deposits with and receivables from broker-dealers, clearing organizations, and counterparties. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also include amounts due from or due to clearing exchanges for daily variation settlements on open futures and options on futures positions. The variation settlements due from or due to clearing exchanges are paid in cash on the following business day. Variation settlements equal the daily settlement of futures contracts and premiums on options on futures contracts. Receivables from broker-dealers and counterparties also include amounts receivable for securities sold but not yet delivered by the Company on settlement date (“fails-to-deliver”) and net receivables arising from unsettled proprietary trades. Payables to broker-dealers and counterparties primarily include amounts payable for securities purchased but not yet received by the Company on settlement date (“fails-to-receive”) and net payables arising from unsettled proprietary trades. Receivables from broker-dealers, clearing organizations and counterparties, and payables to broker-dealers, clearing organizations and counterparties also include amounts related to the value of registered broker-dealer clients cross-currency payment transactions related to the Global Payments segment. These amounts arise due to a clearing period before the funds are received and payments are made, which usually is one to two business days.
Receivable from and Payable to Clients	Receivable from and Payable to Clients Receivable from clients, net of the allowance for doubtful accounts, include the total of net deficits in individual exchange-traded futures and OTC derivative trading accounts carried by the Company. Client deficits arise from realized and unrealized trading losses on client futures, options on futures, swaps and forwards and amounts due on cash and margin transactions. Client deficit accounts are reported gross of client accounts that contain net credit or positive balances, except where a right of offset exists. Net deficits in individual futures exchange-traded and OTC derivative trading accounts include both secured and unsecured deficit balances due from clients as of the balance sheet date. Secured deficit amounts are backed by U.S. Treasury obligations and commodity warehouse receipts. These U.S Treasury obligations and commodity warehouse receipts are not netted against the secured deficit amounts, as the conditions for right of setoff have not been met. See note 13 for additional discussion of client deficit accounts originating in November 2018. Receivable from clients, net also includes the net amounts receivable from securities clients in connection with the settlement of regular-way cash securities, margin loans to clients, and client cash debits. It is the Company’s policy to report margin loans and payables that arise due to positive cash flows in the same client’s accounts on a net basis when the conditions for netting as specified in U.S. GAAP are met. Clients’ securities transactions cleared by the Company are recorded on a settlement date basis. Securities cleared by the Company and pledged to the Company as a condition of the custodial clearing arrangements are owned by the clients, including those that collateralize margin or other similar transactions, and are not reflected on the consolidated balance sheets as the Company does not have title to, or beneficial interests, in those assets. In the event of uncompleted transactions on settlement date, the Company records corresponding receivables and payables, respectively. The carrying value of the receivables and payables approximates fair value due to their short-term nature. Receivables from clients, net also include amounts receivable from non-broker-dealer clients for securities sold but not yet delivered by the Company on settlement date (“fails-to-deliver”) and net receivables arising from unsettled proprietary trades. Payable to clients represent the total of client accounts with credit or positive balances. Client accounts are used primarily in connection with exchange-traded and OTC commodity, foreign exchange, precious metals, and securities transactions and include gains and losses on open trades as well as securities and cash margin deposits made as required by the Company, the exchange-clearing organizations or other clearing organizations. Client accounts with credit or positive balances are reported gross of client deficit accounts, except where a right of offset exists. Payables to broker-dealers and counterparties also includes amounts payable to non-broker-dealer clients for securities purchased but not yet received by the Company on settlement date (“fails-to-receive”) and net payables arising from unsettled proprietary trades. Receivable from and payables to clients also include amounts related to the value of non-registered broker-dealer clients cross-currency payment transactions related to the Global Payments segment. These amounts arise due to a clearing period before the funds are received and payments are made, which usually is one to two business days. The future collectability of receivables from clients can be impacted by the Company’s collection efforts, the financial stability of its clients, and the general economic climate in which it operates. The Company evaluates accounts that it believes may become uncollectible on a specific identification basis, through reviewing daily margin deficit reports, the historical daily aging of the receivables, and by monitoring the financial strength of its clients. The Company may unilaterally close client trading positions in certain circumstances. In addition, to evaluate client margining and collateral requirements, client positions are stress tested regularly and monitored for excessive concentration levels relative to the overall market size. Furthermore, in certain instances, the Company is indemnified, and able to charge back, introducing broker-dealers for bad debts incurred by their clients. The Company generally charges off an outstanding receivable balance when all economic means of recovery have been exhausted. That determination considers information such as the occurrence of significant changes in the client’s financial position such that the client can no longer pay the obligation, or that the proceeds from collateral will not be sufficient to pay the balance.
Notes Receivable	Notes Receivable Accrual of commodity financing income on any note is discontinued when, in the opinion of management, there is reasonable doubt as to the timely collectability of interest or principal. Nonaccrual notes are returned to an accrual status when, in the opinion of management, the financial position of the borrower indicates there is no longer any reasonable doubt as to the timely payment of principal and interest. The Company records a charge against earnings for notes receivable losses when management believes that the collection of outstanding principal is not probable.
Physcial Commodities Inventory	Physical Commodities Inventory Inventories of certain agricultural commodities are carried at net realizable value, which approximates fair value less disposal costs. The agricultural commodities inventories have reliable, readily determinable and realizable market prices, have relatively predictable and insignificant costs of disposal and are available for immediate delivery. Changes in the fair values of these agricultural commodities inventories are included as a component of ‘cost of sales of physical commodities’ in the consolidated income statements. Inventories of energy related products are valued at the lower of cost or net realizable value. Inventories of precious metals held by subsidiaries that are not broker-dealers are valued at the lower of cost or net realizable value, using the weighted-average price and first-in first-out costing method. Precious metals inventory held by StoneX Financial Ltd, a U.K. based broker-dealer subsidiary, is measured at fair value, with changes in fair value included as a component of ‘principal gains, net’ in the consolidated income statements.
Property and Equipment	Property and Equipment Property and equipment is stated at cost, net of accumulated depreciation and amortization and depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized on a straight-line basis over the estimated useful life of the improvement or the term of the lease, whichever is shorter. Expenditures that increase the value or productive capacity of assets are capitalized. When property and equipment are retired, sold, or otherwise disposed of, the asset’s carrying amount and related accumulated depreciation are removed from the accounts and any gain or loss is included in earnings. The Company accounts for costs incurred to develop its trading platforms and related software in accordance with ASC 350-40, Internal-Use Software. ASC 350-40 requires that such technology be capitalized in the application development stages. Costs related to training, administration and non-value added maintenance are charged to expense as incurred. Capitalized software development costs are amortized over the useful life of the software, which the Company estimates at three years. In accordance with ASC 360-10, Property, Plant and Equipment, the Company periodically evaluates the carrying value of long-lived assets when events and circumstances warrant such review. The carrying value of a long-lived asset is considered impaired when the anticipated identifiable undiscounted cash flows from such an asset (or asset group) are less than carrying value. In that event, a loss is recognized in the amount by which the carrying value exceeds fair market value of the long-lived asset. This standard applies to assets held for use and not to assets held for sale.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets Goodwill is the cost of acquired companies in excess of the fair value of identifiable net assets at the acquisition date. Goodwill is not subject to amortization, but rather is evaluated for impairment at least annually. The Company evaluates its goodwill for impairment at the fiscal year end (or more frequently if indicators of potential impairment exist) in accordance with ASC 350, Intangibles - Goodwill and Other. Goodwill impairment is determined by comparing the estimated fair value of a reporting unit with its respective carrying value. If the estimated fair value exceeds the carrying value, goodwill at the reporting unit level is not deemed to be impaired. However, if the estimated fair value is below carrying value, further analysis is required to determine the amount of the impairment. This further analysis involves assigning tangible assets and liabilities, identified intangible assets and goodwill to reporting units and comparing the fair value of each reporting unit to its carrying amount. In the course of the evaluation of the potential impairment of goodwill, the Company may perform either a qualitative or a quantitative assessment. The Company’s qualitative assessment of potential impairment may result in the determination that a quantitative impairment analysis is not necessary. Under this elective process, the Company assesses qualitative factors to determine whether the existence of events or circumstances leads the Company to determine that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If after assessing the totality of events or circumstances, the Company determines it is more likely than not that the fair value of a reporting unit is greater than its carrying amount, then performing a quantitative analysis is not required. However, if the Company concludes otherwise, then the Company performs a quantitative impairment analysis. If the Company either chooses not to perform a qualitative assessment, or the Company chooses to perform a qualitative assessment but is unable to qualitatively conclude that no impairment has occurred, then the Company performs a quantitative evaluation. In the case of a quantitative assessment, the Company estimates the fair value of the reporting unit which the goodwill that is subject to the quantitative analysis is associated (generally defined as the businesses for which financial information is available and reviewed regularly by management) and compares it to the carrying value. If the estimated fair value of a reporting unit is less than its carrying value, the Company estimates the fair value of all assets and liabilities of the reporting unit, including goodwill. If the carrying value of the reporting unit’s goodwill is greater than the estimated fair value, an impairment charge is recognized for the excess. The fair value of the Company’s reporting units exceeded their respective carrying values under the first step of the quantitative assessment and no impairment charges were recorded for any of the periods presented. Identifiable intangible assets subject to amortization are amortized using the straight-line method over their estimated period of benefit, ranging from five to twenty years. Identifiable intangible assets are tested for impairment whenever events or changes in circumstances suggest that an asset’s or asset group’s carrying value may not be fully recoverable. Residual value is presumed to be zero for all identifiable intangible assets.
Financial Instruments Owned and Sold, Not Yet Purchased	Financial Instruments Owned and Sold, Not Yet Purchased Financial instruments owned and sold, not yet purchased, at fair value consist of financial instruments carried at fair value on a recurring basis or amounts that approximate fair value, with related realized and unrealized gains and losses recognized in current period earnings. Realized and unrealized gains and losses on financial instruments owned and sold, not yet purchased, are included in ‘principal gains, net’, ‘interest income’, ‘interest expense’, and ‘cost of sales of physical commodities’ in the consolidated income statements. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties, other than in a forced or liquidation sale. Financial instruments owned and sold, not yet purchased are comprised primarily of the financial instruments held by the Company’s broker-dealer subsidiaries and the Company’s OTC derivative swap dealer. Financial instruments owned and financial instruments sold, not yet purchased, includes trading securities that the Company holds as a principal. The Company has not classified any financial instruments owned or sold, not yet purchased, as available-for-sale or held-to-maturity. Financial instruments owned and sold, not yet purchased includes derivative instruments that the Company holds as a principal which are primarily transacted on an OTC basis. As a derivatives dealer, the Company utilizes derivative instruments to manage exposures to foreign currency, commodity price and interest rate risks for the Company and its clients. The Company’s objectives for holding derivatives include reducing, eliminating, and efficiently managing the economic impact of these exposures as effectively as possible. The Company’s derivative instruments also include forward purchase and sale commitments for the physical delivery of agricultural and energy related commodities in a future period. Contracts to purchase agricultural and energy commodities generally relate to the current or future crop year. Contracts for the sale of agricultural and energy commodities generally do not extend beyond one year. Derivative instruments are recognized as either assets or liabilities and are measured at fair value on a recurring basis. As the Company does not elect hedge accounting for any derivative instruments, realized and unrealized gains and losses from the change in fair value of derivative instruments are recognized immediately in current period earnings. Realized and unrealized gains and losses from the derivative instruments in which the Company acts as a dealer are included within ‘principal gains, net’ on the consolidated income statements. Realized and unrealized gains and losses on firm purchase and sale commitments are included within ‘cost of sales of physical commodities’ on the consolidated income statements. To reduce credit exposure on the derivative instruments for which the Company acts as a dealer, the Company may enter into a master netting arrangement that allows for settlement of all derivative transactions with each counterparty. In addition, the credit support annex that accompanies master netting arrangements allows parties to the master netting agreement to mitigate their credit risk by requiring the party which is out of the money to post collateral. The Company accepts collateral in the form of cash or other marketable securities. Where permitted, the Company elects to net-by-counterparty certain derivative instruments entered into under a legally enforceable master netting agreement and, therefore, the fair value of those derivative instruments are netted by counterparty in the consolidated balance sheets. As the Company elects to net-by-counterparty the fair value of such derivative instruments, the Company also nets-by-counterparty cash collateral exchanged as part of those derivative instruments. The Company also brokers foreign exchange forwards, options and cash, or spot, transactions between clients and external counterparties. A portion of the contracts are arranged on an offsetting basis, limiting the Company’s risk to performance of the two offsetting parties. The offsetting nature of the contracts eliminates the effects of market fluctuations on the Company’s operating results. Due to the Company’s role as a principal participating in both sides of these contracts, the amounts are presented gross on the consolidated balance sheets at their respective fair values, net of offsetting assets and liabilities. The Company holds proprietary positions in its foreign exchange line of business. On a limited basis, the Company’s foreign exchange trade desk will accept a client transaction and will offset that transaction with a similar but not identical position with a counterparty. These unmatched transactions are intended to be short-term in nature and are often conducted to facilitate the most effective transaction for the Company’s client. These spot and forward contracts are accounted for as free-standing derivatives and reported in the consolidated balance sheets at their fair values. The Company may lease commodities to or from clients or counterparties. These commodity leases, which primarily involve precious metals, are recorded at fair value utilizing the fair value option based on guidance in ASC 825-10, Financial Instruments - Fair Value Option. These commodities leases represent hybrid financial instruments which contain both a dollar denominated loan host contract and an embedded forward derivative contract on the underlying commodities, which can be settled in either cash or metals. As permitted by the fair value option election, the entire instrument is recorded at fair value as either an asset or liability in the consolidated balance sheets. The corresponding change in the fair value of the instrument is recognized in the consolidated income statements as a component of ‘principal gains, net’ for the fiscal years ended September 30, 2020, 2019, and 2018. The Company does elect to value all of their commodities lease agreements at fair value using the fair value option.
Exchange and Clearing Organization Memberships	Exchange and Clearing Organization Memberships The Company is required to hold certain exchange and clearing organization memberships and pledges them for clearing purposes, in order to provide the Company the right to process trades directly with the respective venues. Exchange memberships include seats on the Chicago Board of Trade (“CBOT”), the Minneapolis Grain Exchange, the New York Mercantile Exchange (“NYMEX”), the Commodity Exchange, Inc. (“COMEX”) Division of the New York Mercantile Exchange, Mercado de Valores de Buenos Aires S.A. (“MERVAL”), the Chicago Mercantile Exchange (“CME”) Growth and Emerging Markets, InterContinental Exchange, Inc. (“ICE”) Futures US, ICE Europe Ltd and London Metal Exchange (“LME”). Exchange firm and clearing organization common stock include shares of CME Group, Inc., ICE, LME, and the Depository Trust & Clearing Corporation (“DTCC”). Exchange and clearing organization memberships required in order to conduct business through the respective venues are recorded at cost and are included in ‘other assets’ on the consolidated balance sheets. Equity investments in exchange firm common stock not required in order to conduct business on the exchanges are classified as trading securities included within ‘financial instruments owned’ on the consolidated balance sheets and recorded at fair value, with unrealized gains and losses recorded as a component of ‘principal gains, net’ on the consolidated income statements. The fair value of exchange firm common stock not required in order to conduct business on the exchanges is determined from quoted market prices. Exchange memberships that represent (a) both an ownership interest and the right to conduct business in the respective venues and are held for operating purposes, or (b) an ownership interest, which must be held by the Company to conduct business in the respective venues are accounted for as an ownership interest at cost with appropriate consideration for other-than-temporary impairment. The cost of exchange and clearing organization memberships that represent an ownership interest and are required in order to conduct business in the respective venues was $5.6 million as of September 30, 2020 and September 30, 2019 compared to a fair value of $6.7 million and $6.0 million as of September 30, 2020 and September 30, 2019, respectively. Fair value was determined using quoted market prices and recent transactions. Alternatively, exchange memberships, or seats, that only represent the right to conduct business on an exchange, but not an ownership interest in the exchange, are accounted for as intangible assets at cost with potential impairment determined under Accounting Standards Codification 350-30- Intangibles - Goodwill and Other. The cost of exchange memberships required in order to conduct business on the exchange, but that do not represent an ownership interest in the exchange, was $5.8 million as of September 30, 2020 and September 30, 2019. As of September 30, 2020, there were no indicators of impairment that would suggest that the carrying value of exchange memberships that don’t represent an ownership interest are impaired, primarily based upon projections of future cash flows and earnings attributable to access these respective venues.
Product Financing Arrangements	Product Financing Arrangements In the normal course of operations, the Company executes notes receivable under repurchase agreements with clients whereby the clients sell certain commodity inventory or other investments to the Company and agree to repurchase the commodity inventory or investment at a future date at a fixed price. These transactions are short-term in nature, and in accordance with the guidance contained in ASC 860, Transfer and Servicing, are treated as secured borrowings rather than commodity inventory and purchases and sales in the Company’s consolidated financial statements. These transactions are reflected as ‘notes receivable’ in the consolidated balance sheet. Commodities or investments sold under repurchase agreements are reflected at the amount of cash received in connection with the transactions. The Company may be required to provide additional collateral based on the fair value of the underlying asset. The Company also participates in commodity repurchase transactions that are accounted for as commodity inventory and purchases and sales of physical commodities as opposed to secured borrowings. The repurchase price under these arrangements is not fixed at the time of execution and, therefore, do not meet all the criteria to be accounted for as product financing arrangements.
Lenders Under Loans and Senior Secured Borrowings	Lenders Under Loans Lenders under loans are accounted for at amortized cost, which approximates fair value due to their variable rates of interest. Senior Secured Borrowings The senior secured borrowings are accounted for at amortized cost, and are stated net of unamortized deferred financing costs and original issue discount.
Acquisitions and Contingent Consideration	Contingent Consideration The Company estimates and records the acquisition date estimated fair value of contingent consideration as part of purchase price consideration for acquisitions. Additionally, each reporting period, the Company estimates changes in the fair value of contingent consideration, and any change in fair value is recognized in the consolidated income statements. An increase in the contingent consideration expected to be paid will result in a charge to operations in the period that the anticipated fair value of contingent consideration increases, while a decrease in the earn-out expected to be paid will result in a credit to operations in the period that the anticipated fair value of contingent consideration decreases. The estimate of the fair value of contingent consideration requires subjective assumptions to be made of future operating results, discount rates, and probabilities assigned to various potential operating result scenarios.
Cost of Sales of Physical Commodities	Cost of Sales of Physical CommoditiesCost of sales of physical commodities include finished commodity or raw material and processing costs along with operating costs relating to the receipt, storage and delivery of the physical commodities. Cost of sales of physical commodities also includes changes in the fair value of agricultural commodity inventories held for sale, and related forward purchase and sale commitments and exchange-traded futures and options contracts.
Interest Expense	Interest ExpenseInterest expense is recognized on an accrual basis. Interest expense is incurred on outstanding balances on the Company’s credit facilities. Interest expense is also incurred on fixed income securities sold, not yet purchased, that the Company holds in its market-marking businesses. Interest expense is also incurred from collateralized transactions, including securities loaned and securities sold under agreements to repurchase
Compensation and Benefits	Compensation and Benefits Compensation and benefits consists primarily of salaries, incentive compensation, variable compensation, including commissions, related payroll taxes and employee benefits. The Company classifies employees as either risk management consultants / traders, operational or administrative personnel, which includes the executive officers. Variable compensation paid to risk management consultants and traders generally represents a fixed percentage of revenues generated, and in some cases, revenues produced less direct costs and an overhead allocation. The Company accrues commission expense on a trade-date basis.
Share-Based Compensation	Share-Based Compensation The Company accounts for share-based compensation in accordance with the guidance in ASC 718-10, Compensation - Stock Compensation. The cost of employee services received in exchange for a share-based award is generally measured based on the grant-date fair value of the award. Share-based employee awards that require future service are amortized over the relevant service period. Forfeitures are accounted for as they occur in determining share-based employee compensation expense. For option awards granted, compensation cost is recognized on a straight-line basis over the vesting period for the entire award.
Transaction-Based Clearing Expenses	Transaction-Based Clearing Expenses Clearing fees and related expenses include primarily variable expenses for clearing and settlement services, including fees the Company pays to executing brokers, exchanges, clearing organizations and banks. These fees are based on transaction volume, and recorded as expense on the trade date. Clearing fees are passed on to clients and are presented gross in the consolidated statements of income as the Company acts as a principal for these transactions.
Introducing Broker Commissions	Introducing Broker Commissions Introducing broker commissions include commissions paid to non-employee third parties that have introduced clients to the Company. Introducing brokers are individuals or organizations that maintain relationships with clients and accept futures and options orders from those clients. The Company directly provides all account, transaction and margining services to introducing brokers, including accepting money, securities and property from the clients. The commissions are determined and settled monthly.
Income Taxes	Income Taxes Income tax expense includes U.S. federal, state and local and foreign income taxes. Certain items of income and expense are not reported in tax returns and financial statements in the same year. The objectives of accounting for income taxes are to recognize the amount of taxes payable or refundable for the current year. The Company utilizes the asset and liability method to provide income taxes on all transactions recorded in the consolidated financial statements. This method requires that income taxes reflect the expected future tax consequences of temporary differences between the carrying amounts of assets or liabilities for book and tax purposes. Accordingly, a deferred tax asset or liability for each temporary difference is determined based on the tax rates that the Company expects to be in effect when the underlying items of income and expense are realized. Judgment is required in assessing the future tax consequences of events that have been recognized in the Company’s financial statements or tax returns, including the repatriation of undistributed earnings of foreign subsidiaries. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authority, based upon the technical merits of the position. The tax benefit recognized in the consolidated financial statements from such a position is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. See Note 20 for further information on the Company’s income taxes.
Additional Paid-In Capital	Additional Paid-In Capital The Company’s additional paid-in capital (“APIC”) consists of stockholder contributions that are in excess of par value of common stock. Included in APIC are amounts related to the exercise of stock options and amortization of share-based compensation.
Comprehensive Income	Comprehensive Income Comprehensive income consists of net income and other gains and losses affecting stockholders’ equity that, under U.S. GAAP, are excluded from net income. Other comprehensive income (loss) includes net actuarial gains and losses from defined benefit pension plans and gains and losses on foreign currency translations.
Accounting Standards Adopted	Accounting Standards Adopted In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842). This update requires a lessee to recognize on the balance sheet a liability to make lease payments and a corresponding right-of-use asset. The guidance also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases (Topic 842) Targeted Improvements. In March 2019, the FASB issued ASU 2019-01, Leases (Topic 842) Codification Improvements. Among other things, this updated guidance provides an optional transition method, which allows for the initial application of the new accounting standard at the adoption date and the recognition of a cumulative-effect adjustment to the opening balance of retained earnings as of the beginning of the period of adoption. The Company adopted the new ASUs on October 1, 2019, using the effective date modified retrospective transition approach and has not restated comparative periods. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to not reassess contracts to determine if they contain leases, lease classification and initial direct costs. The Company’s application of the new standard resulted in changes to the condensed consolidated balance sheet but did not have an impact on the condensed consolidated income statement. See Note 2 for more information. In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this updated standard allow a reclassification from accumulated other comprehensive loss, net to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. The Company adopted this standard on October 1, 2019 and, as a result, recorded a $0.7 million reclassification between accumulated other comprehensive loss, net and retained earnings.

Description of Business and Significant Accounting Policies (Policies)

12 Months Ended

Sep. 30, 2020

The accompanying consolidated financial statements include the accounts of StoneX Group Inc. and all other entities in which the Company has a controlling financial interest. All material intercompany transactions and balances have been eliminated in consolidation.

Unless otherwise stated herein, all references to fiscal 2020, fiscal 2019, and fiscal 2018 refer to the Company’s fiscal years ended September 30.

In the consolidated income statements, the total revenues reported combine gross revenues for the physical commodities business and net revenues for all other businesses. The subtotal ‘operating revenues’ in the consolidated income statements is calculated by deducting physical commodities cost of sales from total revenues. The subtotal ‘net operating revenues’ in the consolidated income statements is calculated as operating revenues less transaction-based clearing expenses, introducing broker commissions and interest expense. Transaction-based clearing expenses represent variable expenses paid to executing brokers, exchanges, clearing organizations and banks in relation to transactional volumes. Introducing broker commissions include commission paid to non-employee third parties that have introduced clients to the Company. Net operating revenues represent revenues available to pay variable compensation to risk management consultants and traders and direct non-variable expenses, as well as variable and non-variable expenses of operational and administrative employees.

Consolidation

Fiscal Period

Unless otherwise stated herein, all references to fiscal 2020, fiscal 2019, and fiscal 2018 refer to the Company’s fiscal years ended September 30.

Use of Estimates

Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates and assumptions relate to fair value measurements for financial instruments, revenue recognition, the provision for probable losses from bad debts, valuation of inventories, and incomes taxes and contingencies. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. The Company reviews all significant estimates affecting the financial statements on a recurring basis and records the effect of any necessary adjustments prior to their issuance. Although these and other estimates and assumptions are based on the best available information, actual results could be materially different from these estimates.

Reclassifications

During the year ended September 30, 2020, the Company reclassified certain selling and marketing related costs in connection with the acquisition of Gain Capital Holdings, Inc. (“Gain”). In performing this reclassification, the Company has made retrospective adjustments to the consolidated income statements for the years ended September 30, 2019 and 2018. For the years ended September 30, 2019 and 2018, selling and marketing related costs of $5.2 million and $6.2 million, were reclassified from ‘Other’ expense to ‘Selling and marketing’ expense.

During the year ended September 30, 2019, the Company reclassified certain brokerage related revenues for which the Company earns commissions on trading activity in the capacity of an agent. In performing this reclassification, the Company has made a retrospective adjustment to the consolidated income statement for the year ended September 30, 2018. For the year ended September 30, 2018, brokerage related revenue of $35.0 million, was reclassified from ‘principal gains, net’ to ‘commissions and clearing fees’. Additionally, the Company has changed the name of the line item ‘trading gains, net’ to ‘principal gains, net’ on the consolidated income statement in order to reflect the fact that these revenue streams are earned from trading financial instruments in the capacity of a principal and in order to properly segregate revenues earned from contracts with clients.

Foreign Currency Translation

The Company’s consolidated financial statements are reported in U.S. dollars. The Company’s foreign subsidiaries

maintain their records either in U.S. dollars or in certain instances the currency of the country in which they operate. The

method of translating local currency financial information into U.S. dollars depends on whether the economy in which the foreign subsidiary operates has been designated as highly inflationary or not. Economies with a three-year cumulative inflation rate of more than 100% are considered highly inflationary.

Assets and liabilities of foreign subsidiaries in non-highly inflationary economies are translated into U.S. dollars using rates of exchange at the balance sheet date. Translation adjustments are recorded in other comprehensive income (loss). Revenues and expense are translated at rates of exchange in effect during the year. Transaction gains and losses are recorded in earnings.

Foreign subsidiaries that operate in highly inflationary countries use the U.S. dollar as their functional currency. Local currency

monetary assets and liabilities are remeasured into U.S. dollars using rates of exchange as of each balance sheet date, with remeasurement adjustments and other transaction gains and losses recognized in earnings. Nonmonetary assets and liabilities

do not fluctuate with changes in the local currency exchange rates to the dollar as the translated amounts for nonmonetary

assets and liabilities at the end of the accounting period in which the economy becomes highly inflationary becomes the accounting basis for those assets and liabilities in the period of change and subsequent periods. Revenues and expenses are translated at rates of exchange in effect during the year.

The Company operates asset management and debt trading businesses in Argentina through various wholly-owned subsidiaries. Operating revenues from the Argentinean subsidiaries represented approximately 2% of the consolidated operating revenues for the year ended September 30, 2020. The operating environment in Argentina continues to present business challenges, including ongoing devaluation of the Argentine peso and significant inflation. For the year ended September 30, 2018, the Argentine peso declined approximately 139% (from 17.3 to 41.3 pesos to the U.S. dollar). Based upon inflationary data published by the International Practices Task Force of the Center for Audit Quality, the economy of Argentina became highly inflationary during the three months ended June 30, 2018.

Beginning July 1, 2018, the Company designated Argentina’s economy as highly inflationary for accounting purposes. As a result, the Company has accounted for the Argentinean entities using the U.S. dollar as their functional currency beginning in the quarter ending September 30, 2018. Argentine peso-denominated monetary assets and liabilities are remeasured at each balance sheet date to the currency exchange rate then in effect, with currency remeasurement gains and loses recognized in earnings. The translated balances for nonmonetary assets and liabilities as of June 30, 2018, became the accounting basis for those assets in the period of change and subsequent periods

Cash and Cash Equivalents

Cash and Cash Equivalents The Company considers cash held at banks and all highly liquid investments not held for trading purposes, with original or acquired maturities of 90 days or less, including certificates of deposit and money market mutual funds, to be cash and cash equivalents. Cash and cash equivalents consists of cash, certificates of deposit, and money market mutual funds not deposited with or pledged to clearing organizations, broker-dealers, clearing organizations or counterparties, or segregated under federal or other regulations. Certificates of deposit are stated at cost plus accrued interest, which approximates fair value, and may be withdrawn at any time at the discretion of the Company without penalty. Money market mutual funds are stated at their net asset value.

Cash, Securities and Other Assets Segregated under Federal and other Regulations

Cash, Securities and Other Assets Segregated under Federal and other Regulations Pursuant to requirements of the Commodity Exchange Act and Commission Regulation 30.7 of the U.S. Commodity Futures Trading Commission (“CFTC”) in the U.S., the Markets in Financial Instruments Implementing Directive 2006/73/EC underpinning the Client Asset (“CASS”) rules in the Financial Services Authority (“FSA”) handbook in the United Kingdom (“U.K.”), and the Securities & Futures Act (“SFA”) in Singapore, funds deposited by clients relating to futures and options on futures contracts in regulated commodities must be carried in separate accounts which are designated as segregated or secured client accounts. Additionally, in accordance with Rule 15c3-3 of the Securities Exchange Act of 1934 (“Rule 15c3-3”), the Company maintains separate accounts for the exclusive benefit of securities clients and proprietary accounts of broker dealers (“PABs”). Rule 15c3-3 requires the Company to maintain special reserve bank accounts (“SRBAs”) for the exclusive benefit of securities clients and PABs. The deposits in segregated client accounts and SRBAs are not commingled with the funds of the Company. Under the FSA’s rules, certain categories of clients may choose to opt-out of segregation.

Collateralized Transactions

The Company enters into securities purchased under agreements to resell, securities sold under agreements to repurchase, securities borrowed transactions, and securities loaned transactions primarily to fund principal debt trading, acquire securities to cover short positions, acquire securities for settlement, or meet counterparty needs under matched-booked trading strategies.

These transactions are accounted for as collateralized financing transactions and are recorded at their contractual amounts plus accrued interest. In connection with these agreements and transactions, it is the policy of the Company to receive or pledge cash or securities to collateralize such agreements and transactions in accordance with contractual arrangements. The Company monitors the fair value of the collateral on a daily basis and the Company may require counterparties, or may be required by counterparties, to deposit additional collateral or return collateral pledged. Interest income and interest expense are recognized over the life of the arrangements and are recorded in the statement of income as interest income or interest expense, as applicable. The carrying amount of these transactions approximate fair value due to their short-term nature and the level of collateralization. These transactions are reported gross, except when a right of offset exists and the other criteria for netting under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 210-20, Balance Sheet - Offsetting are met.

Deposits with and Receivables from Broker-dealers, Clearing Organizations and Counterparties, and Payables to Broker-dealers, Clearing Organizations and Counterparties

As required by regulations of the CFTC, FSA, and Monetary Authority of Singapore (“MAS”), client funds received to margin, guarantee, and/or secure commodity futures and futures on options as well as retail foreign exchange transactions are segregated and accounted for separately from the general assets of the Company. Deposits with broker-dealers, clearing organizations, and counterparties pertain primarily to deposits made to satisfy margin requirements on client and proprietary open futures and options on futures positions and to satisfy the requirements set by clearing exchanges for clearing membership. The Company also pledges margin deposits with various counterparties for over-the-counter (“OTC”) derivative contracts, and these deposits are also included in deposits with broker-dealers, clearing organizations, and counterparties. The Company also deposits cash margin with various securities clearing organizations as an ongoing condition of the securities clearing relationships, and these deposits are also included in deposits with broker-dealers, clearing organizations, and counterparties. Deposits with and receivables from broker-dealers, clearing organizations, and counterparties are reported gross, except where a right of offset exists. As of September 30, 2020 and September 30, 2019, the Company had cash and cash equivalents on deposit with or pledged to broker-dealers, clearing organizations, and counterparties of approximately 1.6 billion.

Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also includes guaranty deposits with clearing exchanges. The guaranty deposits are held by the clearing exchanges for use in potential default situations by one

or more members of the clearing exchanges. The guaranty deposits may be applied to the Company’s obligations to the clearing exchange, or to the clearing exchange’s obligations to unrelated parties.

Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also include securities pledged to clearing exchanges. These securities are either pledged to the Company by its clients or represent investments of client funds. It is the Company’s practice to include client-owned securities on its consolidated balance sheets, as the rights to those securities have been transferred to the Company under the terms of the futures trading agreements. Securities pledged primarily include U.S. Treasury obligations, foreign government obligations, and certain exchange-traded funds (“ETFs”). Securities that are not client-owned, and represent an investment of client funds, are adjusted to fair value with associated changes in unrealized gains or losses recorded in ‘interest income’ in the consolidated income statements. For client-owned securities, the change in fair value is offset against the payable to clients with no impact recognized in the consolidated income statements. The fair value of these securities included within deposits with and receivables from broker-dealers, clearing organizations, and counterparties was $1,949.3 million and $603.8 million as of September 30, 2020 and September 30, 2019, respectively.

Management has considered guidance required by ASC 860, Transfers and Servicing as it relates to securities pledged by clients to margin their futures and options on futures trading accounts. Based on a review of the agreements with the client, management believes the transferor surrenders control over those assets because: (a) the transferred assets have been isolated from the transferor—put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership, (b) each transferee has the right to pledge or exchange the assets (or beneficial interests) it received, and no condition both constrains the transferee (or holder) from taking advantage of its right to pledge or exchange and provides more than a trivial benefit to the transferor and (c) the transferor does not maintain effective control over the transferred assets through either (1) an agreement that both entitles and obligates the transferor to repurchase or redeem them before their maturity or (2) the ability to unilaterally cause the holder to return specific assets, other than through a cleanup call. Under this guidance, the Company reflects the client collateral assets and corresponding liabilities in the Company’s consolidated balance sheets as of September 30, 2020 and September 30, 2019.

Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also includes amounts due from clearing exchanges for unrealized gains and losses associated with clients’ options on futures contracts. See discussion in the Financial Instruments section below for additional information on the Company’s accounting policies for derivative contracts. For client-owned derivative contracts, the fair value is offset against the payable to clients with no impact recognized on the consolidated income statements.

The Company maintains client omnibus and proprietary accounts with other clearing organizations, and the equity balances in those accounts along with any margin cash or securities deposited with the clearing organizations are included in deposits with and receivables from broker-dealers, clearing organizations, and counterparties.

Deposits with and receivables from broker-dealers, clearing organizations, and counterparties also include amounts due from or due to clearing exchanges for daily variation settlements on open futures and options on futures positions. The variation settlements due from or due to clearing exchanges are paid in cash on the following business day. Variation settlements equal the daily settlement of futures contracts and premiums on options on futures contracts.

Receivables from broker-dealers and counterparties also include amounts receivable for securities sold but not yet delivered by the Company on settlement date (“fails-to-deliver”) and net receivables arising from unsettled proprietary trades.

Payables to broker-dealers and counterparties primarily include amounts payable for securities purchased but not yet received by the Company on settlement date (“fails-to-receive”) and net payables arising from unsettled proprietary trades.

Receivables from broker-dealers, clearing organizations and counterparties, and payables to broker-dealers, clearing organizations and counterparties also include amounts related to the value of registered broker-dealer clients cross-currency payment transactions related to the Global Payments segment. These amounts arise due to a clearing period before the funds are received and payments are made, which usually is one to two business days.

Receivable from and Payable to Clients

Receivable from clients, net of the allowance for doubtful accounts, include the total of net deficits in individual exchange-traded futures and OTC derivative trading accounts carried by the Company. Client deficits arise from realized and unrealized trading losses on client futures, options on futures, swaps and forwards and amounts due on cash and margin transactions. Client deficit accounts are reported gross of client accounts that contain net credit or positive balances, except where a right of offset exists. Net deficits in individual futures exchange-traded and OTC derivative trading accounts include both secured and unsecured deficit balances due from clients as of the balance sheet date. Secured deficit amounts are backed by U.S. Treasury obligations and commodity warehouse receipts. These U.S Treasury obligations and commodity warehouse receipts are not netted against the secured deficit amounts, as the conditions for right of setoff have not been met. See note 13 for additional discussion of client deficit accounts originating in November 2018.

Receivable from clients, net also includes the net amounts receivable from securities clients in connection with the settlement of regular-way cash securities, margin loans to clients, and client cash debits. It is the Company’s policy to report margin loans and payables that arise due to positive cash flows in the same client’s accounts on a net basis when the conditions for netting as specified in U.S. GAAP are met. Clients’ securities transactions cleared by the Company are recorded on a settlement date basis. Securities cleared by the Company and pledged to the Company as a condition of the custodial clearing arrangements are owned by the clients, including those that collateralize margin or other similar transactions, and are not reflected on the consolidated balance sheets as the Company does not have title to, or beneficial interests, in those assets. In the event of uncompleted transactions on settlement date, the Company records corresponding receivables and payables, respectively. The carrying value of the receivables and payables approximates fair value due to their short-term nature.

Receivables from clients, net also include amounts receivable from non-broker-dealer clients for securities sold but not yet delivered by the Company on settlement date (“fails-to-deliver”) and net receivables arising from unsettled proprietary trades.

Payable to clients represent the total of client accounts with credit or positive balances. Client accounts are used primarily in connection with exchange-traded and OTC commodity, foreign exchange, precious metals, and securities transactions and include gains and losses on open trades as well as securities and cash margin deposits made as required by the Company, the exchange-clearing organizations or other clearing organizations. Client accounts with credit or positive balances are reported gross of client deficit accounts, except where a right of offset exists.

Payables to broker-dealers and counterparties also includes amounts payable to non-broker-dealer clients for securities purchased but not yet received by the Company on settlement date (“fails-to-receive”) and net payables arising from unsettled proprietary trades.

Receivable from and payables to clients also include amounts related to the value of non-registered broker-dealer clients cross-currency payment transactions related to the Global Payments segment. These amounts arise due to a clearing period before the funds are received and payments are made, which usually is one to two business days.

The future collectability of receivables from clients can be impacted by the Company’s collection efforts, the financial stability of its clients, and the general economic climate in which it operates. The Company evaluates accounts that it believes may become uncollectible on a specific identification basis, through reviewing daily margin deficit reports, the historical daily aging of the receivables, and by monitoring the financial strength of its clients. The Company may unilaterally close client trading positions in certain circumstances. In addition, to evaluate client margining and collateral requirements, client positions are stress tested regularly and monitored for excessive concentration levels relative to the overall market size. Furthermore, in certain instances, the Company is indemnified, and able to charge back, introducing broker-dealers for bad debts incurred by their clients.

The Company generally charges off an outstanding receivable balance when all economic means of recovery have been exhausted. That determination considers information such as the occurrence of significant changes in the client’s financial position such that the client can no longer pay the obligation, or that the proceeds from collateral will not be sufficient to pay the balance.

Notes Receivable

Accrual of commodity financing income on any note is discontinued when, in the opinion of management, there is reasonable doubt as to the timely collectability of interest or principal. Nonaccrual notes are returned to an accrual status when, in the opinion of management, the financial position of the borrower indicates there is no longer any reasonable doubt as to the timely payment of principal and interest. The Company records a charge against earnings for notes receivable losses when management believes that the collection of outstanding principal is not probable.

Physcial Commodities Inventory

Physical Commodities Inventory

Inventories of certain agricultural commodities are carried at net realizable value, which approximates fair value less disposal costs. The agricultural commodities inventories have reliable, readily determinable and realizable market prices, have relatively predictable and insignificant costs of disposal and are available for immediate delivery. Changes in the fair values of these agricultural commodities inventories are included as a component of ‘cost of sales of physical commodities’ in the consolidated income statements.

Inventories of energy related products are valued at the lower of cost or net realizable value. Inventories of precious metals held by subsidiaries that are not broker-dealers are valued at the lower of cost or net realizable value, using the weighted-average price and first-in first-out costing method. Precious metals inventory held by StoneX Financial Ltd, a U.K. based broker-dealer subsidiary, is measured at fair value, with changes in fair value included as a component of ‘principal gains, net’ in the consolidated income statements.

Property and Equipment

Property and equipment is stated at cost, net of accumulated depreciation and amortization and depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized on a straight-line basis over the estimated useful life of the improvement or the term of the lease, whichever is shorter. Expenditures that increase the value or productive capacity of assets are capitalized. When property and equipment are retired, sold, or otherwise disposed of, the asset’s carrying amount and related accumulated depreciation are removed from the accounts and any gain or loss is included in earnings.

The Company accounts for costs incurred to develop its trading platforms and related software in accordance with ASC 350-40, Internal-Use Software. ASC 350-40 requires that such technology be capitalized in the application development stages. Costs related to training, administration and non-value added maintenance are charged to expense as incurred. Capitalized software development costs are amortized over the useful life of the software, which the Company estimates at three years.

In accordance with ASC 360-10, Property, Plant and Equipment, the Company periodically evaluates the carrying value of long-lived assets when events and circumstances warrant such review. The carrying value of a long-lived asset is considered impaired when the anticipated identifiable undiscounted cash flows from such an asset (or asset group) are less than carrying value. In that event, a loss is recognized in the amount by which the carrying value exceeds fair market value of the long-lived asset. This standard applies to assets held for use and not to assets held for sale.

Goodwill and Identifiable Intangible Assets

Goodwill is the cost of acquired companies in excess of the fair value of identifiable net assets at the acquisition date. Goodwill is not subject to amortization, but rather is evaluated for impairment at least annually.

The Company evaluates its goodwill for impairment at the fiscal year end (or more frequently if indicators of potential impairment exist) in accordance with ASC 350, Intangibles - Goodwill and Other. Goodwill impairment is determined by comparing the estimated fair value of a reporting unit with its respective carrying value. If the estimated fair value exceeds the carrying value, goodwill at the reporting unit level is not deemed to be impaired. However, if the estimated fair value is below carrying value, further analysis is required to determine the amount of the impairment. This further analysis involves assigning tangible assets and liabilities, identified intangible assets and goodwill to reporting units and comparing the fair value of each reporting unit to its carrying amount.

In the course of the evaluation of the potential impairment of goodwill, the Company may perform either a qualitative or a quantitative assessment. The Company’s qualitative assessment of potential impairment may result in the determination that a quantitative impairment analysis is not necessary. Under this elective process, the Company assesses qualitative factors to determine whether the existence of events or circumstances leads the Company to determine that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If after assessing the totality of events or circumstances, the Company determines it is more likely than not that the fair value of a reporting unit is greater than its carrying amount, then performing a quantitative analysis is not required. However, if the Company concludes otherwise, then the Company performs a quantitative impairment analysis.

If the Company either chooses not to perform a qualitative assessment, or the Company chooses to perform a qualitative assessment but is unable to qualitatively conclude that no impairment has occurred, then the Company performs a quantitative evaluation. In the case of a quantitative assessment, the Company estimates the fair value of the reporting unit which the goodwill that is subject to the quantitative analysis is associated (generally defined as the businesses for which financial information is available and reviewed regularly by management) and compares it to the carrying value. If the estimated fair value of a reporting unit is less than its carrying value, the Company estimates the fair value of all assets and liabilities of the reporting unit, including goodwill. If the carrying value of the reporting unit’s goodwill is greater than the estimated fair value, an impairment charge is recognized for the excess. The fair value of the Company’s reporting units exceeded their respective carrying values under the first step of the quantitative assessment and no impairment charges were recorded for any of the periods presented.

Identifiable intangible assets subject to amortization are amortized using the straight-line method over their estimated period of benefit, ranging from five to twenty years. Identifiable intangible assets are tested for impairment whenever events or changes in circumstances suggest that an asset’s or asset group’s carrying value may not be fully recoverable. Residual value is presumed to be zero for all identifiable intangible assets.

Financial Instruments Owned and Sold, Not Yet Purchased

Financial instruments owned and sold, not yet purchased, at fair value consist of financial instruments carried at fair value on a recurring basis or amounts that approximate fair value, with related realized and unrealized gains and losses recognized in current period earnings. Realized and unrealized gains and losses on financial instruments owned and sold, not yet purchased, are included in ‘principal gains, net’, ‘interest income’, ‘interest expense’, and ‘cost of sales of physical commodities’ in the consolidated income statements. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties, other than in a forced or liquidation sale.

Financial instruments owned and sold, not yet purchased are comprised primarily of the financial instruments held by the Company’s broker-dealer subsidiaries and the Company’s OTC derivative swap dealer. Financial instruments owned and financial instruments sold, not yet purchased, includes trading securities that the Company holds as a principal. The Company has not classified any financial instruments owned or sold, not yet purchased, as available-for-sale or held-to-maturity.

Financial instruments owned and sold, not yet purchased includes derivative instruments that the Company holds as a principal which are primarily transacted on an OTC basis. As a derivatives dealer, the Company utilizes derivative instruments to manage exposures to foreign currency, commodity price and interest rate risks for the Company and its clients. The Company’s objectives for holding derivatives include reducing, eliminating, and efficiently managing the economic impact of these exposures as effectively as possible. The Company’s derivative instruments also include forward purchase and sale commitments for the physical delivery of agricultural and energy related commodities in a future period. Contracts to purchase agricultural and energy commodities generally relate to the current or future crop year. Contracts for the sale of agricultural and energy commodities generally do not extend beyond one year.

Derivative instruments are recognized as either assets or liabilities and are measured at fair value on a recurring basis. As the Company does not elect hedge accounting for any derivative instruments, realized and unrealized gains and losses from the change in fair value of derivative instruments are recognized immediately in current period earnings. Realized and unrealized gains and losses from the derivative instruments in which the Company acts as a dealer are included within ‘principal gains, net’ on the consolidated income statements. Realized and unrealized gains and losses on firm purchase and sale commitments are included within ‘cost of sales of physical commodities’ on the consolidated income statements.

To reduce credit exposure on the derivative instruments for which the Company acts as a dealer, the Company may enter into a master netting arrangement that allows for settlement of all derivative transactions with each counterparty. In addition, the credit support annex that accompanies master netting arrangements allows parties to the master netting agreement to mitigate their credit risk by requiring the party which is out of the money to post collateral. The Company accepts collateral in the form of cash or other marketable securities. Where permitted, the Company elects to net-by-counterparty certain derivative instruments entered into under a legally enforceable master netting agreement and, therefore, the fair value of those derivative instruments are netted by counterparty in the consolidated balance sheets. As the Company elects to net-by-counterparty the fair

value of such derivative instruments, the Company also nets-by-counterparty cash collateral exchanged as part of those derivative instruments.

The Company also brokers foreign exchange forwards, options and cash, or spot, transactions between clients and external counterparties. A portion of the contracts are arranged on an offsetting basis, limiting the Company’s risk to performance of the two offsetting parties. The offsetting nature of the contracts eliminates the effects of market fluctuations on the Company’s operating results. Due to the Company’s role as a principal participating in both sides of these contracts, the amounts are presented gross on the consolidated balance sheets at their respective fair values, net of offsetting assets and liabilities.

The Company holds proprietary positions in its foreign exchange line of business. On a limited basis, the Company’s foreign exchange trade desk will accept a client transaction and will offset that transaction with a similar but not identical position with a counterparty. These unmatched transactions are intended to be short-term in nature and are often conducted to facilitate the most effective transaction for the Company’s client. These spot and forward contracts are accounted for as free-standing derivatives and reported in the consolidated balance sheets at their fair values.

The Company may lease commodities to or from clients or counterparties. These commodity leases, which primarily involve precious metals, are recorded at fair value utilizing the fair value option based on guidance in ASC 825-10, Financial Instruments - Fair Value Option. These commodities leases represent hybrid financial instruments which contain both a dollar denominated loan host contract and an embedded forward derivative contract on the underlying commodities, which can be settled in either cash or metals. As permitted by the fair value option election, the entire instrument is recorded at fair value as either an asset or liability in the consolidated balance sheets. The corresponding change in the fair value of the instrument is recognized in the consolidated income statements as a component of ‘principal gains, net’ for the fiscal years ended September 30, 2020, 2019, and 2018. The Company does elect to value all of their commodities lease agreements at fair value using the fair value option.

Exchange and Clearing Organization Memberships

The Company is required to hold certain exchange and clearing organization memberships and pledges them for clearing purposes, in order to provide the Company the right to process trades directly with the respective venues. Exchange memberships include seats on the Chicago Board of Trade (“CBOT”), the Minneapolis Grain Exchange, the New York Mercantile Exchange (“NYMEX”), the Commodity Exchange, Inc. (“COMEX”) Division of the New York Mercantile Exchange, Mercado de Valores de Buenos Aires S.A. (“MERVAL”), the Chicago Mercantile Exchange (“CME”) Growth and Emerging Markets, InterContinental Exchange, Inc. (“ICE”) Futures US, ICE Europe Ltd and London Metal Exchange (“LME”). Exchange firm and clearing organization common stock include shares of CME Group, Inc., ICE, LME, and the Depository Trust & Clearing Corporation (“DTCC”).

Exchange and clearing organization memberships required in order to conduct business through the respective venues are recorded at cost and are included in ‘other assets’ on the consolidated balance sheets. Equity investments in exchange firm common stock not required in order to conduct business on the exchanges are classified as trading securities included within ‘financial instruments owned’ on the consolidated balance sheets and recorded at fair value, with unrealized gains and losses recorded as a component of ‘principal gains, net’ on the consolidated income statements. The fair value of exchange firm common stock not required in order to conduct business on the exchanges is determined from quoted market prices.

Exchange memberships that represent (a) both an ownership interest and the right to conduct business in the respective venues and are held for operating purposes, or (b) an ownership interest, which must be held by the Company to conduct business in the respective venues are accounted for as an ownership interest at cost with appropriate consideration for other-than-temporary impairment. The cost of exchange and clearing organization memberships that represent an ownership interest and are required in order to conduct business in the respective venues was $5.6 million as of September 30, 2020 and September 30, 2019 compared to a fair value of $6.7 million and $6.0 million as of September 30, 2020 and September 30, 2019, respectively. Fair value was determined using quoted market prices and recent transactions.

Alternatively, exchange memberships, or seats, that only represent the right to conduct business on an exchange, but not an ownership interest in the exchange, are accounted for as intangible assets at cost with potential impairment determined under Accounting Standards Codification 350-30- Intangibles - Goodwill and Other. The cost of exchange memberships required in order to conduct business on the exchange, but that do not represent an ownership interest in the exchange, was $5.8 million as of September 30, 2020 and September 30, 2019. As of September 30, 2020, there were no indicators of impairment that would suggest that the carrying value of exchange memberships that don’t represent an ownership interest are impaired, primarily based upon projections of future cash flows and earnings attributable to access these respective venues.

Product Financing Arrangements

In the normal course of operations, the Company executes notes receivable under repurchase agreements with clients whereby the clients sell certain commodity inventory or other investments to the Company and agree to repurchase the commodity inventory or investment at a future date at a fixed price. These transactions are short-term in nature, and in accordance with the guidance contained in ASC 860, Transfer and Servicing, are treated as secured borrowings rather than commodity inventory and purchases and sales in the Company’s consolidated financial statements. These transactions are reflected as ‘notes receivable’ in the consolidated balance sheet. Commodities or investments sold under repurchase agreements are reflected at the amount of cash received in connection with the transactions. The Company may be required to provide additional collateral based on the fair value of the underlying asset.

The Company also participates in commodity repurchase transactions that are accounted for as commodity inventory and purchases and sales of physical commodities as opposed to secured borrowings. The repurchase price under these arrangements is not fixed at the time of execution and, therefore, do not meet all the criteria to be accounted for as product financing arrangements.

Lenders Under Loans and Senior Secured Borrowings

Lenders Under Loans

Lenders under loans are accounted for at amortized cost, which approximates fair value due to their variable rates of interest.

Senior Secured Borrowings

The senior secured borrowings are accounted for at amortized cost, and are stated net of unamortized deferred financing costs and original issue discount.

Acquisitions and Contingent Consideration

Contingent Consideration

The Company estimates and records the acquisition date estimated fair value of contingent consideration as part of purchase price consideration for acquisitions. Additionally, each reporting period, the Company estimates changes in the fair value of contingent consideration, and any change in fair value is recognized in the consolidated income statements. An increase in the contingent consideration expected to be paid will result in a charge to operations in the period that the anticipated fair value of contingent consideration increases, while a decrease in the earn-out expected to be paid will result in a credit to operations in the period that the anticipated fair value of contingent consideration decreases. The estimate of the fair value of contingent consideration requires subjective assumptions to be made of future operating results, discount rates, and probabilities assigned to various potential operating result scenarios.

Cost of Sales of Physical Commodities

Cost of Sales of Physical CommoditiesCost of sales of physical commodities include finished commodity or raw material and processing costs along with operating costs relating to the receipt, storage and delivery of the physical commodities. Cost of sales of physical commodities also includes changes in the fair value of agricultural commodity inventories held for sale, and related forward purchase and sale commitments and exchange-traded futures and options contracts.

Interest Expense

Interest ExpenseInterest expense is recognized on an accrual basis. Interest expense is incurred on outstanding balances on the Company’s credit facilities. Interest expense is also incurred on fixed income securities sold, not yet purchased, that the Company holds in its market-marking businesses. Interest expense is also incurred from collateralized transactions, including securities loaned and securities sold under agreements to repurchase

Compensation and Benefits

Compensation and benefits consists primarily of salaries, incentive compensation, variable compensation, including commissions, related payroll taxes and employee benefits. The Company classifies employees as either risk management consultants / traders, operational or administrative personnel, which includes the executive officers. Variable compensation paid to risk management consultants and traders generally represents a fixed percentage of revenues generated, and in some cases, revenues produced less direct costs and an overhead allocation. The Company accrues commission expense on a trade-date basis.

Share-Based Compensation

The Company accounts for share-based compensation in accordance with the guidance in ASC 718-10, Compensation - Stock Compensation. The cost of employee services received in exchange for a share-based award is generally measured based on the grant-date fair value of the award. Share-based employee awards that require future service are amortized over the relevant

service period. Forfeitures are accounted for as they occur in determining share-based employee compensation expense. For option awards granted, compensation cost is recognized on a straight-line basis over the vesting period for the entire award.

Transaction-Based Clearing Expenses

Clearing fees and related expenses include primarily variable expenses for clearing and settlement services, including fees the Company pays to executing brokers, exchanges, clearing organizations and banks. These fees are based on transaction volume, and recorded as expense on the trade date. Clearing fees are passed on to clients and are presented gross in the consolidated statements of income as the Company acts as a principal for these transactions.

Introducing Broker Commissions

Introducing broker commissions include commissions paid to non-employee third parties that have introduced clients to the Company. Introducing brokers are individuals or organizations that maintain relationships with clients and accept futures and options orders from those clients. The Company directly provides all account, transaction and margining services to introducing brokers, including accepting money, securities and property from the clients. The commissions are determined and settled monthly.

Income Taxes

Income tax expense includes U.S. federal, state and local and foreign income taxes. Certain items of income and expense are not reported in tax returns and financial statements in the same year. The objectives of accounting for income taxes are to recognize the amount of taxes payable or refundable for the current year. The Company utilizes the asset and liability method to provide income taxes on all transactions recorded in the consolidated financial statements. This method requires that income taxes reflect the expected future tax consequences of temporary differences between the carrying amounts of assets or liabilities for book and tax purposes. Accordingly, a deferred tax asset or liability for each temporary difference is determined based on the tax rates that the Company expects to be in effect when the underlying items of income and expense are realized. Judgment is required in assessing the future tax consequences of events that have been recognized in the Company’s financial statements or tax returns, including the repatriation of undistributed earnings of foreign subsidiaries. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authority, based upon the technical merits of the position. The tax benefit recognized in the consolidated financial statements from such a position is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. See Note 20 for further information on the Company’s income taxes.

Additional Paid-In Capital

The Company’s additional paid-in capital (“APIC”) consists of stockholder contributions that are in excess of par value of common stock. Included in APIC are amounts related to the exercise of stock options and amortization of share-based compensation.

Comprehensive Income

Comprehensive income consists of net income and other gains and losses affecting stockholders’ equity that, under U.S. GAAP, are excluded from net income. Other comprehensive income (loss) includes net actuarial gains and losses from defined benefit pension plans and gains and losses on foreign currency translations.

Accounting Standards Adopted

In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842). This update requires a lessee to recognize on the balance sheet a liability to make lease payments and a corresponding right-of-use asset. The guidance also requires certain qualitative and quantitative disclosures about the amount, timing and uncertainty of cash flows arising from leases. In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases (Topic 842) Targeted Improvements. In March 2019, the FASB issued ASU 2019-01, Leases (Topic 842) Codification Improvements. Among other things, this updated guidance provides an optional transition method, which allows for the initial application of the new accounting standard at the adoption date and the recognition of a cumulative-effect adjustment to the opening balance of retained earnings as of the beginning of the period of adoption. The Company adopted the new ASUs on October 1, 2019, using the effective date modified retrospective transition approach and has not restated comparative periods. The Company elected the package of practical expedients permitted under

the transition guidance within the new standard, which among other things, allowed the Company to not reassess contracts to determine if they contain leases, lease classification and initial direct costs. The Company’s application of the new standard resulted in changes to the condensed consolidated balance sheet but did not have an impact on the condensed consolidated income statement. See Note 2 for more information.

In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this updated standard allow a reclassification from accumulated other comprehensive loss, net to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. The Company adopted this standard on October 1, 2019 and, as a result, recorded a $0.7 million reclassification between accumulated other comprehensive loss, net and retained earnings.