Berkshire 13F Mirror
13f mirrorquarterlyactivesince 2026-07-02universe: Berkshire Hathaway 13F top holdings
The prompt (verbatim — this is the strategy)
Hard limits enforced by a validator, not by the model: long-only; no leverage; max 50% per position.
Claude Sonnet 5
Current holdings
| Ticker | Shares | Value | % of portfolio | Since bought |
|---|---|---|---|---|
| AAPL Apple Inc | 77.528 | $24,085 | 24.0% | -0.64% |
| AXP American Express Company | 53.956 | $18,862 | 18.8% | -1.81% |
| KO Coca-Cola Company | 153.568 | $12,907 | 12.8% | +1.31% |
| BAC Bank Of America Corp | 175.125 | $10,483 | 10.4% | -0.07% |
| OXY Occidental Petroleum Corp | 147.921 | $7,645 | 7.6% | +5.88% |
| CVX Chevron Corp | 43.546 | $7,577 | 7.5% | +3.52% |
| GOOGL Alphabet Inc - Class A | 17.846 | $6,550 | 6.5% | +0.16% |
| CB Chubb Ltd | 13.099 | $4,706 | 4.7% | +0.78% |
| MCO Moody`s Corp | 9.042 | $4,525 | 4.5% | +0.34% |
| KHC Kraft Heinz Company | 123.288 | $3,119 | 3.1% | +1.93% |
| Cash | -$0 | -0.0% |
Decision log
2026-07-02 — traded (10 orders)
This is the initial build of the portfolio to mirror Berkshire Hathaway's latest 13F filing (holdings as of March 31, 2026, filed May 15, 2026). The filing lists 12 disclosed positions, but per the strategy we only hold the top 10 by filed value: Apple, American Express, Coca-Cola, Bank of America, Chevron, Occidental Petroleum, Alphabet, Chubb, Moody's, and Kraft Heinz. DaVita and Kroger rank 11th and 12th by value and are excluded from the top-10 list. All tickers here are tradeable (no nulls), so we can fully replicate this slice. Each holding's dollar value from the filing was rescaled so the top-10 sum to 100% of the portfolio, preserving their relative proportions (e.g., Apple is roughly 1.7x American Express's weight, matching the filing). Starting from an all-cash portfolio, we buy into each position at these target weights, which sum exactly to 100% with no leftover cash, fully investing per the 'no minimum cash' rule while staying within the 50% single-position cap (largest position, Apple, is about 24%).
| Ticker | Side | Target weight | Status |
|---|---|---|---|
| AAPL Apple Inc | buy | 24.2% | filled |
| AXP American Express Company | buy | 19.2% | filled |
| KO Coca-Cola Company | buy | 12.7% | filled |
| BAC Bank Of America Corp | buy | 10.5% | filled |
| CVX Chevron Corp | buy | 7.3% | filled |
| OXY Occidental Petroleum Corp | buy | 7.2% | filled |
| GOOGL Alphabet Inc - Class A | buy | 6.5% | filled |
| CB Chubb Ltd | buy | 4.7% | filled |
| MCO Moody`s Corp | buy | 4.5% | filled |
| KHC Kraft Heinz Company | buy | 3.1% | filled |
Validator rejections: final portfolio weights sum to 1.0002 — exceeds 1 (no leverage / min cash)