Berkshire Hathaway: shared risks

Sample report · top 26 holdings · 13F for 30 Jun 2026

Fifteen risks that two or more holdings name in their own 10-Ks: how likely and how bad we estimate each is, then who filed it.

Filedserif, copied from the 10-KOur estimatemono, with its range

What could happen, and how bad

Our estimate

Each circle is a risk the holdings share. Tap one to see who filed it.

Read the matrix as a table

Import tariffs: likelihood 9/10 (about 95%), impact 5/10, severity 45

Crude oil price: likelihood 6/10 (about 35%), impact 5/10, severity 30

App Store terms: likelihood 7/10 (about 65%), impact 4/10, severity 28; a chatbot missed it

Western wildfires: likelihood 8/10 (about 80%), impact 3/10, severity 24; a chatbot missed it

Digital Markets Act: likelihood 7/10 (about 55%), impact 3/10, severity 21

Florida hurricane: likelihood 5/10 (about 21%), impact 4/10, severity 20; a chatbot missed it

Ad spending: likelihood 4/10 (about 12%), impact 5/10, severity 20; a chatbot missed it

GLP-1 drugs: likelihood 10/10 (about 97%), impact 2/10, severity 20

PFAS rules: likelihood 9/10 (about 85%), impact 2/10, severity 18; a chatbot missed it

China–Taiwan: likelihood 2/10 (about 3%), impact 8/10, severity 16; a chatbot missed it

Delta–AmEx cobrand: likelihood 3/10 (about 8%), impact 5/10, severity 15

Google search case: likelihood 2/10 (about 3%), impact 7/10, severity 14

Earthquakes: likelihood 2/10 (about 4%), impact 6/10, severity 12; a chatbot missed it

Basel III capital: likelihood 3/10 (about 10%), impact 4/10, severity 12

Amazon / AWS: likelihood 6/10 (about 40%), impact 2/10, severity 12; a chatbot missed it

Who in the book is exposed

Filed

Holdings by weight down the side; the same fifteen risks across, most severe first and numbered as on the matrix. A filled square means that company's own 10-K names the risk. Tap it to read the sentence.

Use the arrow keys to move through the grid and Enter to open the filings.

How we score

Two inks: Serif text in quotation marks is a sentence a company filed, copied word for word, with its section and filing date. Monospaced scores are what we estimate, each with its range across three scorers and the reasoning behind it.
Likelihood: The chance the event happens within the next 12 months, scored from 1 to 10 with the percentage it stands for. Anchored to base rates where they exist, and marked as judgment where they don't. The score is not itself a percentage: a 5 stands for a 20–35% chance, a 9 for 80–95%.
Impact: How much of the book is exposed and how hard, read from what the filings say, from 1 to 10.
Severity: Likelihood × impact. It sets the order of the risks and the density of the yellow.
Three scorers: Each risk is scored by three independent scorers. The circle sits on the median; the whiskers show the range.
Chatbot check: We also gave a chatbot only the list of holdings, no filings, and asked what risks they share. A dot on a circle's rim marks a risk it didn't name: what the filings show that a free chatbot wouldn't tell you.
The book: Berkshire Hathaway's top 26 stocks in its 13F for 30 Jun 2026, each weighted by its share of those 26. A circle's area is the share of that book exposed: the holdings whose 10-Ks name the risk, less any the event we scored would not reach.