A friend asks:
Is the portfolio you own with shares of Berkshire Hathaway diversified enough to be your entire equity portfolio?
Here’s my response, with a bit of added color versus my original reply. It’s helpful to have Berkshire’s top 13F holdings (included below) for reference:
Do I think you could buy today’s Berkshire 13F portfolio and hold it forever as a well-diversified portfolio? No. There’s no such thing as a permanent stock portfolio. Capital markets are far too dynamic for that.
What you’re really buying (and thus have to underwrite) with a share of Berkshire are Warren and Charlie’s capital allocation skills. This is an extremely concentrated portfolio. Not necessarily a bad thing for skilled investment managers like Warren and Charlie. But just a handful of stocks and their idiosyncratic characteristics are going to drive portfolio performance.
Do I believe you could plausibly own Berkshire and only Berkshire as a kind of closed-end fund/ETF managed by Warren and Charlie? Yes, I do. The obvious issue you run into here is that sooner or later Warren and Charlie are going to shuffle off this mortal coil. I suspect it’ll be much tougher for investors to maintain the same level of conviction in their successors.
Would I do it myself? No. It’s an awful lot of single manager risk to take, to just own Berkshire. Even if Warren and Charlie were immortal, it would be a lot of single manager risk to take. However, I could definitely see using Berkshire alongside just a couple other highly concentrated managers, if you’re the kind of investor who doesn’t mind high tracking error and is concerned more with the risk of permanent capital impairment than volatility.
Could you potentially just use Berkshire in place of an allocation to large cap US stocks? Yes, I definitely think you could.
The answer to this question really hinges on your definition of risk, and issues of path dependency in investment performance. In my view, the starting point for any asset allocation should be the global market capitalization weighted portfolio. Deviations from the global market capitalization weighted portfolio should be made thoughtfully, after careful deliberation. Whenever you deviate from the global market capitalization weighted portfolio, you are implicitly saying you’re smarter than the aggregated insights of every other market participant.
Sorry to say, but you’re probably not that smart. I’m probably not that smart, either.
To concentrate an investment portfolio in a single share of Berkshire implies you have a massively differentiated view of where value will accrue in the global equity markets, and that you’re extremely confident in that view. In hindsight, it seems obvious Berkshire would be a great bet. But in financial markets, literally everything seems obvious in hindsight.
Does this mean a concentrated bet on Berkshire wouldn’t work out?
Absolutely not. It just means we need to carefully consider whether a highly concentrated bet on Berkshire makes sense in light of its potential performance across a broad range of possible futures.
Personally, I’m not confident enough in my ex ante stock and manager selection abilities to bet the farm on a single pick like that.
And I think that’s true for most of us.