I don't know how long you plan to hold this but from their prospectus:

Important Information Regarding the Fund

The Direxion Monthly 10 Year Note Bear 2X Fund (the “Fund”) seeks calendar month leveraged investment results. The pursuit of calendar month leveraged goals means that the Fund is riskier than alternatives that do not use leverage because the Fund’s objective is to magnify the performance of the NYSE Current 10-Year U.S. Treasury Index. The pursuit of calendar month leveraged investment goals means that the return of the Fund for a period longer than a full calendar month may bear no resemblance to –200% of the return of the NYSE Current 10-Year U.S. Treasury Index for such longer period because the aggregate return of the Fund is the product of the series of calendar month leveraged returns for each calendar month. The path of the benchmark during the longer period may be at least as important to the Fund’s return for the longer period as the cumulative return of the benchmark for the relevant longer period, especially in periods of market volatility. Further, the return for investors that invest for periods less than a full calendar month or for a period different than a calendar month will not be the product of the return of the Fund’s stated goal and the performance of the target index for the full calendar month.

The Fund is designed to be utilized only by knowledgeable investors who understand the potential consequences of seeking calendar month leveraged investment results, understand the risks associated with shorting and the use of leverage and are willing to monitor their portfolios frequently. (Their bolding, not mine)

And:

Total Annual Fund Operating Expenses(2)
1.90%

More:

As a result, over time, the cumulative percentage increase or decrease in the value of the Fund’s portfolio may diverge significantly from the cumulative percentage increase or decrease in the multiple of the return of the Fund’s underlying index due to the compounding effect of losses and gains on the returns of the Fund. It also is expected that the Fund’s use of leverage will cause the Fund to underperform the compounded return of two times its benchmark in a trendless or flat market. (bolding mine this time)

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1.9% is a lot to pay for that risk. How much time decay are you willing to risk?