The table below describes the fees and expenses that you pay if you buy and hold shares of the Fund (“Shares”). Investors may pay brokerage commissions on their purchases and sales of Shares.

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

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2015-09-30

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it purchases and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may result in higher transaction costs and higher taxes when Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, may affect the Fund’s performance. This Fund is newly offered. Therefore, it does not have a turnover rate to report for the most recent fiscal year.

Expense Exchange Traded Fund Commissions [Text]

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This example does not take into account brokerage commissions that you pay when purchasing or selling Shares.

Other Expenses, New Fund, Based on Estimates [Text]

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“Other Expenses” are based on estimated amounts for the current fiscal year.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account brokerage commissions that you pay when purchasing or selling Shares.

The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your Shares at the end of those periods. The example also assumes that your investment has a 5% annual return and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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The Fund is an actively-managed exchange-traded fund (“ETF”) that will invest under normal circumstances primarily (at least 80% of its assets) in domestic and foreign equity securities of companies across multiple sectors, including healthcare, information technology, materials, energy and consumer discretionary, that are relevant to the Fund’s investment theme of the genomics revolution (“Genomics Revolution Companies”).

Companies relevant to this theme are those that the Adviser believes are substantially focused on and are expected to substantially benefit from extending and enhancing the quality of human and other life by incorporating technological and scientific developments, improvements and advancements in genomics into their business, such as by offering new products or services that rely on genomic sequencing, analysis, synthesis or instrumentation. These companies may include ones that develop, produce, manufacture or significantly rely on or enable bionic devices, bio-inspired computing, bioinformatics, molecular medicine and agricultural biotechnology.

In selecting companies that the Adviser believes are relevant to a particular investment theme, it seeks to identify, using its own internal research and analysis, companies capitalizing on disruptive innovation or that are enabling the further development of a theme in the markets in which they operate. The Adviser’s internal research and analysis leverages insights from diverse sources, including external research, to develop and refine its investment themes and identify and take advantage of trends that have ramifications for individual companies or entire industries. The Adviser will use both “top down” (macro-economic and business cycle analysis) and “bottom up” (valuation, fundamental and quantitative measures) approaches to select investments for the Fund. The Fund may invest in certain companies that the Adviser believes are well-positioned to capitalize on and expected to devote substantial efforts to business lines enabled by disruptive genomic innovation, even if such companies do not currently derive a substantial portion of their revenues from genomics related activities.

Under normal circumstances, substantially all of the Fund’s assets will be invested in equity securities, including common stocks, partnership interests, business trust shares and other equity investments or ownership interests in business enterprises. The Fund’s investments will include issuers of micro-, small-, medium- and large-capitalizations. The Fund’s investments in foreign equity securities will be in both developed and emerging markets. The Fund currently intends to use only American Depositary Receipts (“ADRs”) when purchasing foreign securities.

The Fund will be concentrated in issuers in any industry or group of industries in the health care sector, including, in particular, issuers having their principal business activities in the biotechnology industry. Other industries in the health care sector include medical laboratories and research and drug manufacturers.

Strategy Portfolio Concentration [Text]

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Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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There is no assurance that the Fund will meet its investment objective. The value of your investment in the Fund, as well as the amount of return you receive on your investment in the Fund, may fluctuate significantly. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. Therefore, you should consider carefully the following risks before investing in the Fund.

Emerging Market Securities Risk . Investment in securities of emerging market issuers may present risks that are greater than or different from those associated with foreign securities due to less developed and liquid markets and such factors as increased economic, political, regulatory, or other uncertainties.

Equity Securities Risk. The value of the equity securities the Fund holds may fall due to general market and economic conditions, perceptions regarding the industries in which the issuers of securities the Fund holds participate or factors relating to specific companies in which the Fund invests. An unfavorable earnings report or a failure to make anticipated dividend payments by an issuer held by the Fund may affect the value of the Fund’s investment. Equity securities may also be particularly sensitive to general movements in the stock market, and a decline in the broader market may affect the value of the Fund’s equity investments.

Foreign Securities Risk. Investments in the securities of foreign issuers involve risks beyond those associated with investments in U.S. securities. These additional risks include greater market volatility, the availability of less reliable financial information, higher transactional costs, potentially higher custody costs, taxation by foreign governments, decreased market liquidity and political and economic instability. Because the Fund investments in foreign securities currently are made through the purchase of ADRs, the Fund normally will not be hedging any foreign currency exposure (since ADRs are denominated and pay dividends in US dollars).

Future Expected Genomic Business Risk. The Adviser expects to invest at least 80% of the Fund’s assets in Genomics Revolution Companies. However, certain of these companies do not currently derive a substantial portion of their current revenues from genomic-focused businesses and there is no assurance that any company will do so in the future, which may adversely affect the ability of the Fund to achieve its investment objective.

Health Care Sector Risk . The health care sector may be affected by government regulations and government health care programs, restrictions on government reimbursement for medical expenses, increases or decreases in the cost of medical products and services and product liability claims, among other factors. Many health care companies are (i) heavily dependent on patent protection and intellectual property rights and the expiration of a patent may adversely affect their profitability, (ii) subject to extensive litigation based on product liability and similar claims, and (iii) subject to competitive forces that may make it difficult to raise prices and, in fact, may result in price discounting. Many health care products and services may be subject to regulatory approvals. The process of obtaining such approvals may be long and costly, and delays or failure to receive such approvals may negatively impact the business of such companies. Additional or more stringent laws and regulations enacted in the future could have a material adverse effect on such companies in the health care sector. In addition, issuers in the health care sector include issuers having their principal activities in the biotechnology industry, medical laboratories and research, drug laboratories and research and drug manufacturers, which have the additional risks described below.

Biotechnology Company Risk. A biotechnology company’s valuation can often be based largely on the potential or actual performance of a limited number of products and can accordingly be greatly affected if one of its products proves unsafe, ineffective or unprofitable. Biotechnology companies are subject to regulation by, and the restrictions of, the Food and Drug Administration, the Environmental Protection Agency, state and local governments, and foreign regulatory authorities.

Pharmaceutical Company Risk. Companies in the pharmaceutical industry can be significantly affected by government approval of products and services, government regulation and reimbursement rates, product liability claims, patent expirations and protection and intense competition.

Issuer Risk. Because a Fund may invest in approximately 40 to 50 issuers, it is subject to the risk that the value of the Fund’s portfolio may decline due to a decline in value of the equity securities of particular issuers. The value of an issuer’s equity securities may decline for reasons directly related to the issuer, such as management performance and reduced demand for the issuer’s goods or services.

Large-Capitalization Companies Risk. Large-capitalization companies tend to be less volatile than companies with smaller market capitalizations. In exchange for this potentially lower risk, the value of a large-capitalization company may not rise as much as that of a company with a smaller market capitalization.

Management Risk. As an actively-managed ETF, the Fund is subject to management risk. Although the portfolio manager has significant investment management experience, the Adviser is newly-formed and has no prior experience managing actively-managed ETFs. The ability of the Adviser to successfully implement the Fund’s investment strategies will significantly influence the Fund’s performance.

Market Risk . The value of the Fund’s assets will fluctuate as the markets in which the Fund invests fluctuate. The value of the Fund’s investments may decline, sometimes rapidly and unpredictably, simply because of economic changes or other events that affect large portions of the market.

Market Trading Risk. The Fund faces numerous market trading risks, including disruptions to the creation and redemption processes of the Fund, losses from trading in secondary markets, the existence of extreme market volatility or potential lack of an active trading market for Shares, which may result in Shares trading at a significant premium or discount to their net asset value (“NAV”). If a shareholder purchases Shares at a time when the market price is at a premium to the NAV or sells Shares at a time when the market price is at a discount to the NAV, the shareholder may sustain losses.

Micro-Capitalization Companies Risk. Micro-capitalization companies are subject to substantially greater risks of loss and price fluctuations because their earnings and revenues tend to be less predictable (and some companies may be experiencing significant losses). Their share prices tend to be more volatile and their markets less liquid than companies with larger market capitalizations. The shares of micro-capitalization companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the future ability to sell these securities.

New Fund Risk. There can be no assurance that the Fund will grow to or maintain an economically viable size. The Fund may liquidate and terminate at any time without shareholder approval.

Non-Diversified Risk. The Fund is classified as a “non-diversified” investment company under the 1940 Act. Therefore, the Fund may invest a relatively higher percentage of its assets in a relatively smaller number of issuers or may invest a larger proportion of its assets in a single issuer. As a result, the gains and losses on a single investment may have a greater impact on the Fund’s NAV and may make the Fund more volatile than more diversified funds.

Small- and Medium-Capitalization Companies Risk . Small- and medium-capitalization companies may be more volatile and more likely than large-capitalization companies to have narrower product lines, fewer financial resources, less management depth and experience and less competitive strength. Returns on investments in securities of small- and medium-capitalization companies could trail the returns on investments in securities of large-capitalization companies.

Risk Lose Money [Text]

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You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments.

Risk Nondiversified Status [Text]

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The Fund is classified as a “non-diversified” investment company under the 1940 Act. Therefore, the Fund may invest a relatively higher percentage of its assets in a relatively smaller number of issuers or may invest a larger proportion of its assets in a single issuer. As a result, the gains and losses on a single investment may have a greater impact on the Fund’s NAV and may make the Fund more volatile than more diversified funds.

Bar Chart and Performance Table [Heading]

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Performance

Performance One Year or Less [Text]

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The Fund has not yet commenced operations and therefore does not have a performance history. Once available, the Fund’s performance information will be accessible on the Fund’s website at http://ark-invest.com.

Performance Availability Website Address [Text]

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http://ark-invest.com.

Performance Narrative [Text Block]

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ARK Genomic Revolution Multi-Sector ETF (Prospectus Summary) | ARK Genomic Revolution Multi-Sector ETF | ARK Genomic Revolution Multi-Sector ETF

Risk/Return:

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Shareholder Fees (fees paid directly from your investment)

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None

Management Fee

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0.95%

Distribution and/or Service (12b-1) Fees

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none

Other Expenses

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0.50%

^[1]

Total Annual Fund Operating Expenses

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1.45%

Expense Reduction

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0.50%

^[2]

Net Annual Fund Operating Expenses

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0.95%

Expense Example, with Redemption, 1 Year

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$ 97

Expense Example, with Redemption, 3 Years

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$ 409

[1]

The Fund bears other expenses that are not covered under the management fee, which may vary and affect the total level of expenses paid by the Fund, such as taxes and governmental fees, brokerage fees, commissions and other transaction expenses, certain custodial fees and expenses, costs of borrowing money, including interest expenses, and extraordinary expenses (such as litigation and indemnification expenses) (“Fund Expenses”). “Other Expenses” are based on estimated amounts for the current fiscal year.

[2]

ARK Investment Management LLC (“Adviser”) has contractually agreed, until September 30, 2015, to waive or limit its management fee or reimburse the Fund to the extent that various organizational and other expenses of the Fund (excluding Fund Expenses detailed in footnote (a) above) exceed 0.95% (“Expense Limit”) of the Fund’s average net assets. Under the Expense Limitation Agreement, which, after the initial term, renews annually for a full year unless terminated by the Adviser upon at least 30 days’ notice prior to the end of the contract term, the Adviser may recoup these waivers and reimbursements in future periods, not exceeding three years, provided organizational and other Fund expenses plus such recoupment, do not exceed the Expense Limit.