To add some more info - you may already by aware of these facts:
- ETNs have a formula which dictates their NAV and do not actually hold any assets
- The issuers of ETFs publish daily holdings files. You may need to be an affiliated party to access this data.
- To understand roughly what a 1.5 levered ETF like UVXY is holding, you can look at the daily composition of VXX (defined in their prospectus) and assume UVXY holds the same blend of futures. You’ll then find the the Shares Outstanding times the NAV is the total amount of assets that the fund holds. This will almost exactly be 1/1.5 times the notional value of the futures (hence why it is a 1.5 levered product).