Taking ZST, 3 x bear of silver, as an example. If you get in the right direction, it works fine. However, there are two questions:
1. What happen if you are wrong ?
2. How large a position you are able to commit ?
If answer to either of these two questions is not positive, then any gain is rather limited.
Now, taking another angle. Say you are long on silver and thus build a sizable position. On the other hand, you are not sure of short term direction of silver. Then, ZST is useful as a hedge.
Now, if ZST position is static, the hedging is probably meaningless. If fully hedged, summary result is zero. If partially hedged, it is just an offset of volatility. Therefore, the question is if ZST can serve as a hedge AND a trade position, to a certain degree.
Obviously, any 3 x bear has high volatility and thus high premium for calls. One potential way is to sell off money covered call positions. This way you get some profits while waiting for the raging bull to come back.
Silver is not exactly a good example since it is unknown if long-term bull is true or not. S&P 500 probably is a better example. Or better yet, some specific industries that are being beaten down....
Now, you can build a trade position that probably makes some sense and with controlled risks. The bottom line of such position is a commitment in something ...
While doing this regular trading, one probably can spend time on financial reports of companies and probably will gain insight one day on great companies like apple in its early stage ...