I have 20 ETFs in my portfolio. Each has a specific target weight. On purpose, the total % adds up to more than 100%.
I used the free version of Quantrx Portfolio Planner to pick ETFs so they are at most weakly correlated.
In one of his books, William Bernstein found the longer between rebalancing, the better the overall return. In the limit, the best interval for rebalancing is never.
So, I don’t rebalance. Whenever I have money to invest - 401K, dividends, interest, capital gains, etc, I update my ETFs NAVs, then use Morning Star to find the underweighted ETF with the worst 30 day trailing return to invest the new cash in.
The last time around, my worst performer was energy. It was down about half and shortly after my limit order executed, it’s shot up like a rocket.
I don’t always get those immediately phenomenal results but almost every time I buy the worst performer, it quickly turns around, sometimes to fast for my limit order to execute.
It’s my understanding that leveraged funds, and all flavors of inverse funds are extremely expensive and aren’t good long term holdings.