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Welcome to 13F Chat AI

Ask about Berkshire Hathaway, Top 20 US Stocks, S&P 500 holdings, risk, factor style, and optimization results.

HoldingsRiskOptimization

13F.chat — AI Research Terminal for 13F

A new AI frontier for quantitative investing turns any investment idea into unprecedented quantitative investing

Enter a thesis, constraint, or challenging investment idea. 13F.chat turns it into fund screens, holdings insight, and testable optimization paths.

Data as of 2026-05-07114 funds

Research feed

Hot Optimization and Insight Reads

A compact feed that alternates tested strategy pages with fund-level AI insight pages.

Latest research

Fresh Optimizations and Insights

The newest strategy runs and AI-written fund observations, split into two fast-scanning lists.

Holdings movement

What Changed Recently

Largest position changes, ranked by absolute weight delta, from the latest filings across all 73 funds.

TickerActionChangeDateFund
YETIIncrease+9.37 pts2025-12-31Glenn Welling - Engaged Capital
NVIDIAIncrease+6.96 pts2025-12-31Duan Yongping - H&H International Investment
BACExit+6.37 pts2025-12-31Guy Spier - Aquamarine Capital
NVIDIANew+5.88 pts2025-12-31S&P 500 Growth
RBCIncrease+4.34 pts2025-12-31Henry Ellenbogen - Durable Capital Partners
ALCNew+3.69 pts2025-12-31AKO Capital
AMZNDecrease+2.76 pts2025-12-31AltaRock Partners
ASMLDecrease+2.40 pts2025-12-31Pat Dorsey - Dorsey Asset Management
OMFIncrease+2.03 pts2025-12-31Glenn Greenberg - Brave Warrior Advisors
LADIncrease+2.00 pts2025-12-31Greg Alexander - Conifer Management

Strategy lab

Strategy Optimization Results

Average metrics across all 73 funds for each of the four bootstrap strategies — a baseline view for comparison.

MethodAlphaSharpeMax DDAnn. returnFunds
Baseline+0.66%0.67-35.05%11.33%114
Momentum Screen+1.39%0.60-42.35%12.88%114
Value Screen-1.34%0.51-50.04%9.95%114
Combo Equal+1.26%0.65-42.11%13.46%114

Reading 13F

Why 13F Needs AI Context

13F is public data, but not an action signal. Use 13F.chat to chat with AI and turn raw filings into investable insight — three caveats are worth keeping in mind before you act.

Disclosure delay

13F is reported up to 45 days after quarter end — by the time you see it, the manager may have already moved. Use 13F.chat AI to surface the changes that still matter.

Long positions only

13F does not include shorts, derivatives, or foreign assets — you are looking at part of the picture. Chat with our AI to fill the gaps with peer overlap and sector context.

Research signal, not a buy signal

Treat 13F as a starting point for fundamental research and combine it with valuation and momentum context. 13F.chat AI does that synthesis for you.

Browse

Explore the Universe

Search across all 114 funds by name, manager, or ticker — or jump straight into one of the curated slices below.

This content is for informational and research purposes only and is not investment advice.