Methodology

Data Sources & How We Compute Whale Analytics

Last updated: June 29, 2026

This page documents where Whale Analyzer's data comes from, how the derived analytics on each stock and investor page are calculated, and — importantly — the limitations of working from public disclosures. Transparency about method is part of being a trustworthy research tool.

Primary data source: SEC 13F filings

Institutional investment managers that exercise discretion over more than US$100 million in qualifying assets are required to file a Form 13F with the U.S. Securities and Exchange Commission each calendar quarter. The filing lists the manager's long positions in Section 13(f) securities, including reported value and share count as of the end of the quarter. We ingest these filings from SEC EDGAR for the investors tracked on this site.

The 45-day lag: 13F reports are due within 45 days of quarter end. That means every position on this site is a historical snapshot, not a real-time position. Use the data to understand institutional positioning after the fact, never as a live trade signal.

Other disclosure sources

Some profiles are based on other public disclosures rather than 13F — for example SEC Form 4 insider transactions or publicly reported congressional trading disclosures. Each investor profile is labeled with its data source and status so you always know what you are looking at. Where a profile has no local holdings snapshot yet, it is maintained as a discovery/watchlist entry rather than presented as a complete fund.

Price data

Current prices shown on stock pages come from our daily price snapshot. Historical prices used inside the cost-basis reconstruction (below) use a quarter-close price, specifically the quarter-close low where an exact transaction price is unavailable, to keep cost estimates conservative.

How the derived analytics are computed

Each stock and investor page combines the raw filings above with the following derived metrics, all computed from the public data we hold:

Ownership concentration — the share of aggregate reported value held by the single largest, top five, and top ten tracked institutions. Useful for judging whether a name is narrowly or broadly held by whales.
Whale activity this quarter — counts of holders who increased, reduced, initiated (new), or held a position, plus each holder's quarter-over-quarter share change. A net "buying" or "selling" label summarizes the direction.
Cost basis vs current price — an estimated weighted-average cost basis across tracked holders, compared with the current price to show whether the stock trades above or below the aggregate whale cost basis. Entries with missing or non-positive cost data are excluded.
Sector positioning — the stock's sector alongside other tracked names in the same sector, so ownership can be compared across peers.
Investor portfolio analytics — concentration, sector tilt, a turnover proxy from reported buys and sells, and a cost-basis profit-and-loss summary per manager.

Cost-basis reconstruction method

Whale Analyzer reconstructs an estimated average cost per share by replaying each manager's quarterly transaction history: additions are valued at the relevant quarter's close price (quarter-close low where a precise price is unavailable), and reductions and exits are netted against the running basis. This produces an approximate cost basis and unrealized P&L percentage. It is an estimate built from quarterly snapshots and will differ from a manager's true internal cost; treat it as directional, not exact.

Update cadence

13F holdings refresh quarterly, shortly after each filing deadline. Price snapshots update on trading days. Derived analytics (concentration, activity, cost basis) recompute automatically whenever the underlying holdings or prices refresh.

Known limitations

Stale by design. 13F data lags 45+ days and excludes short positions, non-13(f) securities, and positions below reporting thresholds. Real exposure can differ materially.
Estimated, not audited. Cost basis, P&L percentages, and turnover are reconstructed approximations, not figures reported by the manager.
Coverage gaps. Cost-basis data is available for most but not all tracked investors; tickers held only by uncovered investors omit the cost-basis section. Preferred-share and odd share-class tickers are excluded from flagship rankings.
Not investment advice. See our disclaimer. Nothing here is a recommendation to buy, sell, or hold any security.

Corrections

If you spot a data error or have a source correction, email leo.bikotech@gmail.com and we will review it.