Lubar & Co., Inc reported Berkshire Hathaway Inc. (BRK/A) in 2 quarterly 13F filings from 2025 Q4 through 2026 Q1. Peak portfolio weight reached 12.07% in 2026 Q1. The latest visible filing shows BRK/A at 12.07% of the fund.
This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings.
This page is designed to answer the real investor question behind a 13F filing: how meaningful was Lubar & Co., Inc's position in Berkshire Hathaway Inc., and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.
BRK/A was reported at 12.07% of portfolio in the most recent visible filing.
Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.
Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.
Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.
As of 2026 Q1 β sorted by position size
These are the practical questions this page is built to answer before you even open the full history table.
Lubar & Co., Inc reported BRK/A across 2 quarterly 13F filings, from 2025 Q4 through 2026 Q1.
The largest reported portfolio weight for BRK/A was 12.07% in 2026 Q1.
The most recent filing on this page is 2026 Q1, when Lubar & Co., Inc reported 20 shares, equal to 12.07% of portfolio, with an estimated market value of $14.4M.
The chart compares Lubar & Co., Inc's quarterly BRK/A portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.