Organization	3 Months Ended
Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	(1) Organization SIT RISING RATE ETF (the “Fund”), a series of the ETF Managers Group Commodity Trust I (a Delaware statutory trust formed on July 23, 2014), commenced investment operations on February 19, 2015. The Trust also includes one additional series, the Breakwave Dry Bulk Shipping ETF (“BDRY”) that may be publicly offered in the future, but the Fund is currently the Trust’s only publicly offered series. The Fund offers common units of beneficial interest (the “Shares”) only to certain eligible financial institutions (the “Authorized Participants”) in one or more blocks of 50,000 Shares (a “Creation Basket”). ETF Managers Capital LLC (the “Sponsor”), a Delaware limited liability company and a wholly owned subsidiary of Exchange Traded Managers Group LLC, serves as the managing owner and commodity pool operator of the Fund. The Sponsor seeded the Fund with a capital contribution of $1,000 in exchange for 40 Shares (Founders Shares) at the initial issuance price of $25.00 per share on September 26, 2014. Sit Fixed Income Advisors II, LLC (“Sit”) is registered as a “commodity trading advisor” and acts as such for the Fund. On January 8, 2015, Sit increased the seeding of the Fund with a capital contribution of $5,000,000 at the initial issuance price of $25.00 per share. From September 26, 2014 through February 18, 2015 the Fund had no operating activities. The Fund commenced investment operations on February 19, 2015. The Fund commenced trading on the NYSE Arca, Inc. (the “NYSE Arca”) on February 19, 2015 and trades under the symbol “RISE”. Sit is paid a fee equal to 0.50% per annum, effective January 27, 2016, of the value of the Fund’s average daily net assets for its services as the commodity trading advisor to the Fund, payable by the Fund. Sit is a subsidiary of Sit Investment Associates, Inc. The fee payable to Sit has been waived through September 30, 2017. The Fund’s investment objective is to profit from rising interest rates by tracking the performance of a portfolio (the “Benchmark Portfolio”) consisting of exchange traded futures contracts and options on futures on 2, 5 and 10 year U.S. Treasury securities (“Treasury Instruments”) weighted to achieve a targeted negative 10-year average effective portfolio duration (the “Benchmark Component Instruments”). The Fund seeks to achieve its investment objective by investing in the Benchmark Component Instruments currently constituting the Benchmark Portfolio. The Benchmark Portfolio is maintained by Sit and will be rebalanced, reconstituted, or both, monthly (typically on the 15th of each month and on the next business day if the 15th is a holiday, weekend, or other day on which the national exchanges are closed) to maintain a negative 10-year average effective duration. The Benchmark Portfolio and the Fund will each maintain a short position in Treasury Instruments. The Fund does not use futures contracts or options to obtain leveraged investment results. The Fund will not invest in swaps or other over the counter derivative instruments. The weighting of the Treasury Instruments constituting the Benchmark Component Instruments will be based on each maturity’s duration contribution. The expected range for the duration weighted percentage of the 2 year and 5 year maturity Treasury Instruments will be from 30% to 70%. The expected range for the duration weighted percentage of the 10-year maturity Treasury Instruments will be from 5% to 25%. The relative weightings of the Benchmark Component Instruments will be shifted between maturities when there are material changes in the shape of the yield curve, for example, if the Federal Reserve began raising short term interest rates more than long term interest rates. In such an instance, Sit, which maintains the Benchmark Portfolio, will elect to increase the weightings of the 2 year and reduce the weighting in the 10-year maturity. Conversely, Sit will do the opposite if the Federal Reserve began raising long term interest rates more than short term interest rates. Reconstitution and rebalancing each will occur monthly, on the 15th, except for as noted above or if there are radical changes in the yield curve such that effective duration is outside of a range from negative nine to negative 11-year average effective duration, in which case Sit will adjust the maturities of the Treasury Instruments before the next expected monthly reconstitution. The Sponsor anticipates that approximately 5% to 15% of the Fund’s assets will be used as payment for or collateral for Treasury Instruments. In order to collateralize its Treasury Instrument positions, the Fund will hold such assets, from which it will post margin to its futures commission merchant (“FCM”), SG Americas Securities, LLC, in an amount equal to the margin required by the relevant exchange, and transfer to its FCM any additional amounts that may be separately required by the FCM. When establishing positions in Treasury Instruments, the Fund will be required to deposit initial margin with a value of approximately 3% to 10% of the value of each Treasury Instrument position at the time it is established. These margin requirements are subject to change from time to time by the exchange or the FCM. On a daily basis, the Fund will be obligated to pay, or entitled to receive, variation margin in an amount equal to the change in the daily settlement level of its Treasury Instruments positions. Any assets not required to be posted as margin with the FCM will be held at the Fund’s administrator in cash or cash equivalents as discussed below. The Benchmark Portfolio will be invested in Benchmark Component Instruments and rebalanced, as noted above to maintain a negative average effective portfolio duration of approximately 10 years. Duration is a measure of estimated price sensitivity relative to changes in interest rates. Portfolios with longer durations are typically more sensitive to changes in interest rates. For example, if interest rates rise by 1%, the market value of a security with an effective duration of 5 years would decrease by 5%, with all other factors being constant, and likewise the market value of a security with an effective duration of negative 5 years would increase by 5%, with all other factors being constant. The correlation between duration and price sensitivity is greater for securities rated investment-grade than it is for securities rated below investment-grade. Duration estimates are based on assumptions by Sit and are subject to a number of limitations. Effective duration is calculated based on historical price changes of U.S. Treasuries and Treasury Instruments held by the Benchmark Portfolio, and therefore is a more accurate estimate of price sensitivity provided interest rates remain within their historical range. Investments in debt securities typically decrease in value when interest rates rise. The risk is usually greater for longer-term debt securities. The Fund will incur certain expenses in connection with its operations. The Fund will hold cash or cash equivalents such as U.S. Treasuries or other high credit quality, short-term fixed-income or similar securities for direct investment or as collateral for the Treasury Instruments and for other liquidity purposes and to meet redemptions that may be necessary on an ongoing basis. These expenses and income from the cash and cash equivalent holdings may cause imperfect correlation between changes in the Fund’s net asset value (“NAV”) and changes in the Benchmark Portfolio, because the Benchmark Portfolio does not reflect expenses or income. The Fund seeks to trade its positions prior to maturity; accordingly, natural market forces may cost the Fund while rebalancing. Each time the Fund seeks to reconstitute its positions, barring movement in the underlying securities, the futures and option prices may be higher or lower. Such differences in price, barring a movement in the price of the underlying security, will constitute “roll yield” and may inhibit the Fund’s ability to achieve its investment objective. Several factors determine the total return from investing in a futures contract position. One factor that impacts the total return that will result from investing in near month futures contracts and “rolling” those contracts forward each month is the price relationship between the current near month contract and the next month contract. When the Fund purchases an option that expires “out of the money,” the Fund will realize a loss. The Fund may not be able to invest the its assets in futures and options contracts having an aggregate notional amount exactly equal to that which is required to achieve a negative 10-year average effective duration. For example, as standardized contracts, U.S. Treasury futures contracts are denominated in specific dollar amounts, and the Fund’s NAV and the proceeds from the sale of a Creation Basket are unlikely to be an exact multiple of the amounts of those contracts. As a result, in such circumstances, the Fund may be better able to achieve the exact amount of exposure desired through the use of other investments. The Sponsor will close existing positions when it determines it would be appropriate to do so and reinvest the proceeds in other positions. Positions may also be closed out to meet orders for Redemption Baskets.

Organization

3 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

(1) Organization

SIT RISING RATE ETF (the “Fund”), a series of the ETF Managers Group Commodity Trust I (a Delaware statutory trust formed on July 23, 2014), commenced investment operations on February 19, 2015. The Trust also includes one additional series, the Breakwave Dry Bulk Shipping ETF (“BDRY”) that may be publicly offered in the future, but the Fund is currently the Trust’s only publicly offered series. The Fund offers common units of beneficial interest (the “Shares”) only to certain eligible financial institutions (the “Authorized Participants”) in one or more blocks of 50,000 Shares (a “Creation Basket”). ETF Managers Capital LLC (the “Sponsor”), a Delaware limited liability company and a wholly owned subsidiary of Exchange Traded Managers Group LLC, serves as the managing owner and commodity pool operator of the Fund. The Sponsor seeded the Fund with a capital contribution of $1,000 in exchange for 40 Shares (Founders Shares) at the initial issuance price of $25.00 per share on September 26, 2014. Sit Fixed Income Advisors II, LLC (“Sit”) is registered as a “commodity trading advisor” and acts as such for the Fund. On January 8, 2015, Sit increased the seeding of the Fund with a capital contribution of $5,000,000 at the initial issuance price of $25.00 per share. From September 26, 2014 through February 18, 2015 the Fund had no operating activities.

The Fund commenced investment operations on February 19, 2015. The Fund commenced trading on the NYSE Arca, Inc. (the “NYSE Arca”) on February 19, 2015 and trades under the symbol “RISE”.

Sit is paid a fee equal to 0.50% per annum, effective January 27, 2016, of the value of the Fund’s average daily net assets for its services as the commodity trading advisor to the Fund, payable by the Fund. Sit is a subsidiary of Sit Investment Associates, Inc. The fee payable to Sit has been waived through September 30, 2017.

The Fund’s investment objective is to profit from rising interest rates by tracking the performance of a portfolio (the “Benchmark Portfolio”) consisting of exchange traded futures contracts and options on futures on 2, 5 and 10 year U.S. Treasury securities (“Treasury Instruments”) weighted to achieve a targeted negative 10-year average effective portfolio duration (the “Benchmark Component Instruments”). The Fund seeks to achieve its investment objective by investing in the Benchmark Component Instruments currently constituting the Benchmark Portfolio. The Benchmark Portfolio is maintained by Sit and will be rebalanced, reconstituted, or both, monthly (typically on the 15th of each month and on the next business day if the 15th is a holiday, weekend, or other day on which the national exchanges are closed) to maintain a negative 10-year average effective duration. The Benchmark Portfolio and the Fund will each maintain a short position in Treasury Instruments. The Fund does not use futures contracts or options to obtain leveraged investment results. The Fund will not invest in swaps or other over the counter derivative instruments.

The weighting of the Treasury Instruments constituting the Benchmark Component Instruments will be based on each maturity’s duration contribution. The expected range for the duration weighted percentage of the 2 year and 5 year maturity Treasury Instruments will be from 30% to 70%. The expected range for the duration weighted percentage of the 10-year maturity Treasury Instruments will be from 5% to 25%. The relative weightings of the Benchmark Component Instruments will be shifted between maturities when there are material changes in the shape of the yield curve, for example, if the Federal Reserve began raising short term interest rates more than long term interest rates. In such an instance, Sit, which maintains the Benchmark Portfolio, will elect to increase the weightings of the 2 year and reduce the weighting in the 10-year maturity. Conversely, Sit will do the opposite if the Federal Reserve began raising long term interest rates more than short term interest rates. Reconstitution and rebalancing each will occur monthly, on the 15th, except for as noted above or if there are radical changes in the yield curve such that effective duration is outside of a range from negative nine to negative 11-year average effective duration, in which case Sit will adjust the maturities of the Treasury Instruments before the next expected monthly reconstitution.

The Sponsor anticipates that approximately 5% to 15% of the Fund’s assets will be used as payment for or collateral for Treasury Instruments. In order to collateralize its Treasury Instrument positions, the Fund will hold such assets, from which it will post margin to its futures commission merchant (“FCM”), SG Americas Securities, LLC, in an amount equal to the margin required by the relevant exchange, and transfer to its FCM any additional amounts that may be separately required by the FCM. When establishing positions in Treasury Instruments, the Fund will be required to deposit initial margin with a value of approximately 3% to 10% of the value of each Treasury Instrument position at the time it is established. These margin requirements are subject to change from time to time by the exchange or the FCM. On a daily basis, the Fund will be obligated to pay, or entitled to receive, variation margin in an amount equal to the change in the daily settlement level of its Treasury Instruments positions. Any assets not required to be posted as margin with the FCM will be held at the Fund’s administrator in cash or cash equivalents as discussed below.

The Benchmark Portfolio will be invested in Benchmark Component Instruments and rebalanced, as noted above to maintain a negative average effective portfolio duration of approximately 10 years. Duration is a measure of estimated price sensitivity relative to changes in interest rates. Portfolios with longer durations are typically more sensitive to changes in interest rates. For example, if interest rates rise by 1%, the market value of a security with an effective duration of 5 years would decrease by 5%, with all other factors being constant, and likewise the market value of a security with an effective duration of negative 5 years would increase by 5%, with all other factors being constant. The correlation between duration and price sensitivity is greater for securities rated investment-grade than it is for securities rated below investment-grade.

Duration estimates are based on assumptions by Sit and are subject to a number of limitations. Effective duration is calculated based on historical price changes of U.S. Treasuries and Treasury Instruments held by the Benchmark Portfolio, and therefore is a more accurate estimate of price sensitivity provided interest rates remain within their historical range. Investments in debt securities typically decrease in value when interest rates rise. The risk is usually greater for longer-term debt securities.

The Fund will incur certain expenses in connection with its operations. The Fund will hold cash or cash equivalents such as U.S. Treasuries or other high credit quality, short-term fixed-income or similar securities for direct investment or as collateral for the Treasury Instruments and for other liquidity purposes and to meet redemptions that may be necessary on an ongoing basis. These expenses and income from the cash and cash equivalent holdings may cause imperfect correlation between changes in the Fund’s net asset value (“NAV”) and changes in the Benchmark Portfolio, because the Benchmark Portfolio does not reflect expenses or income.

The Fund seeks to trade its positions prior to maturity; accordingly, natural market forces may cost the Fund while rebalancing. Each time the Fund seeks to reconstitute its positions, barring movement in the underlying securities, the futures and option prices may be higher or lower. Such differences in price, barring a movement in the price of the underlying security, will constitute “roll yield” and may inhibit the Fund’s ability to achieve its investment objective.

Several factors determine the total return from investing in a futures contract position. One factor that impacts the total return that will result from investing in near month futures contracts and “rolling” those contracts forward each month is the price relationship between the current near month contract and the next month contract.

When the Fund purchases an option that expires “out of the money,” the Fund will realize a loss. The Fund may not be able to invest the its assets in futures and options contracts having an aggregate notional amount exactly equal to that which is required to achieve a negative 10-year average effective duration. For example, as standardized contracts, U.S. Treasury futures contracts are denominated in specific dollar amounts, and the Fund’s NAV and the proceeds from the sale of a Creation Basket are unlikely to be an exact multiple of the amounts of those contracts. As a result, in such circumstances, the Fund may be better able to achieve the exact amount of exposure desired through the use of other investments.

The Sponsor will close existing positions when it determines it would be appropriate to do so and reinvest the proceeds in other positions. Positions may also be closed out to meet orders for Redemption Baskets.