Yes, you can.  You can trade what you want. As these ETFs are specialised in nature, we request confirmation that you are comfortable with the risks attached to them.  

So from the team here at Stake, please make sure your understand the products you trade and risks associated with them.

Here is a little snippet from FINRA about these products:

Leveraged, inverse, and inverse leveraged ETFs seek to achieve a daily return that is a multiple, inverse, or inverse multiple of the daily return of a securities index.  These ETFs are a subset of index-based ETFs because they track a securities index.  They seek to achieve their stated objectives on a daily basis.  Investors should be aware that the performance of these ETFs over a period longer than one day will probably differ significantly from their stated daily performance objectives.  These ETFs often employ techniques such as engaging in short sales and using swaps, futures contracts and other derivatives that can expose the ETF, and by extension the ETF investors, to a host of risks.  As such, these are specialized products that typically are not suitable for buy-and-hold investors.