Throughout January these Friday Files are taking on the form of my “Annual Review” of my holdings, which will culminate in a clearer listing of what I own and focus on, including portfolio allocations that I have personally, and a clearer delineation between the stuff I write about because it’s interesting, and the stuff I write about and focus more on because I’m invested in it or am seriously considering investing in it.

The last two weeks have been focused on natural resources and mining, and on technology, two of my fairly large sector allocations — the other two sectors where I have fairly large exposure will be covered this week and next, they are “Insurance” and insurance-centered conglomerates, and, broadly speaking, “income” stocks that are followed largely because of high current income (mostly REITs right now). I’m going to hold off the “income” sector for one more week, because I’m curious to see whether the opening days of the Trump presidency have any impact on interest rates and those stocks are almost all very much impacted by long-term interest rates, so today we’re looking at what is actually my largest sector allocation: Insurance.

Insurance has almost always been a pretty substantial part of my portfolio, though that’s largely because of two big positions that I have held in insurance companies for more than ten years — those are Berkshire Hathaway (BRK-B), which is much less insurance-driven today than it was even a decade ago, thanks largely to major acquisitions of industrial and capital-intensive companies like Burlington Northern and Precision Castparts, and Markel (MKL), which emulates Berkshire in many ways but is far less diversified and is still overwhelmingly a property and casualty insurance business.

I’ve also added positions in two other oddball insurance-focused conglomerates in the more recent past in Fairfax Financial and Fosun, and I also have a position in the TARP Warrants issued by AIG, which is the most mainstream and “vanilla” of the insurers in this list. Others have come and gone over the years, including positions in the two hedge fund-driven reinsurance companies Third Point Re (TPRE) and Greenlight Re (GLRE) that I’ve sold in the past year or two, but those five positions encompass what I own now in the sector.

In general, insurance companies get valued based on a few things:

Their underwriting prowess over time, which is ...