ValueSider Superinvestor Data

Dynamically fetches portfolio and trading activity for value investors (Superinvestors) from ValueSider, based on SEC 13F filings. Real-time flow: fetch page with web_fetch → parse with script → return JSON.

When to use

• User asks for a Superinvestor / guru portfolio (e.g. Warren Buffett, Mason Hawkins, Longleaf Partners).
• User asks for 13F holdings or what stocks does [manager/fund] own.
• User asks for buy/sell activity (what is [guru] buying or selling).
• User mentions ValueSider or valuesider.com in the context of portfolio data.

Real-time flow (recommended)

ValueSider often returns 403 for direct HTTP requests. Use web fetch to get page content, then parse with the script.

Step 1: Resolve guru slug

• If the user gave a name (e.g. "Mason Hawkins"), use a known slug such as mason-hawkins-longleaf-partners, or fetch https://valuesider.com/value-investors with web_fetch and find the matching link (slug is the path between /guru/ and /portfolio).
• Common slugs: warren-buffett-berkshire-hathaway, mason-hawkins-longleaf-partners, seth-klarman-baupost-group, bill-ackman-pershing-square-capital-management.

Step 2: Fetch both pages with web_fetch

• Portfolio: https://valuesider.com/guru/{guru_slug}/portfolio
• Activity: https://valuesider.com/guru/{guru_slug}/portfolio-activity

Call web_fetch (or equivalent) for each URL and keep the returned text content.

Step 3: Parse content to JSON

Save the portfolio response to a temp file (e.g. _portfolio.txt), activity to _activity.txt. Then run:

# From the skill directory (valuesider-superinvestor-data/)
python scripts/parse_fetched_content.py --type portfolio --file _portfolio.txt --guru-slug <guru_slug> --source-url "https://valuesider.com/guru/<guru_slug>/portfolio"
python scripts/parse_fetched_content.py --type activity --file _activity.txt --guru-slug <guru_slug> --source-url "https://valuesider.com/guru/<guru_slug>/portfolio-activity"

Or pipe content from stdin (no --file):

python scripts/parse_fetched_content.py --type portfolio --guru-slug mason-hawkins-longleaf-partners < _portfolio.txt

Output is JSON: portfolio has summary + holdings; activity has activities (quarter, ticker, stock_name, activity_type, share_change, pct_change_to_portfolio, reported_price, pct_of_portfolio).

Step 4: Present results

Summarize summary (period, portfolio value, number of holdings), list top holdings or recent buys/sells from the parsed JSON. Data is from ValueSider; do not present as financial advice.

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Alternative: direct fetch script (when not 403)

If the environment allows (e.g. no 403), you can use the request-based script:

# List gurus (may 403)
python scripts/fetch_valuesider.py --list-gurus --limit 100

# Fetch one guru (may 403)
python scripts/fetch_valuesider.py <guru_slug>
python scripts/fetch_valuesider.py <guru_slug> --portfolio-only
python scripts/fetch_valuesider.py <guru_slug> --activity-only

Requires: pip install -r requirements.txt (requests, beautifulsoup4). On 403, use the real-time flow above instead.

Data source

• Portfolio: https://valuesider.com/guru/{guru_slug}/portfolio
• Activity: https://valuesider.com/guru/{guru_slug}/portfolio-activity
• Guru list: https://valuesider.com/value-investors