The theory behind investing in a multi-asset portfolio is pretty straight forward when simplifying it. You select a diverse set of uncorrelated assets, assign target weights and then you're done. Not that tricky.
It is mostly the managing part of the investment process that is more challenging. First, you have to work on your conviction to stick to the strategy and remembering why you chose the strategy in the first place. Secondly, you have to deal with rebalancing the portfolio, as uncorrelated assets are guaranteed to develop in different directions with some assets zigging when others are zagging.
The topic of rebalancing is one which I find is underserved in the literature and one that I get most questions about. Usually, it is the theory behind a portfolio that is the most exciting to write about and which is the key topic that sells and attracts more clients. The science of rebalancing, however, is just something that is covered briefly, at most.
While I have been writing about portfolio rebalancing in the past, I have recently found renewed inspiration for this topic. That inspiration turned into this post, where we are looking more closely at rebalancing luck, and if there is an optimal time in a month to rebalance a portfolio.