Quantisnow Insider Buying Index

An insider purchase is a Form 4 filed with the SEC whose non-derivative table reports an open-market purchase (transaction code P) by an officer, director or 10% owner. Quantisnow parses every Form 4 from EDGAR as it is accepted, computes the dollar value of each transaction (shares times reported price), and tags filings with a purchase as the Insider Buy category.

Purchase value sums those reported dollar values across all purchase filings in the month. Sale value does the same for open-market sales (transaction code S) on every other Form 4, so tax withholding, option exercises, grants and gifts are excluded from both sides. Transactions reported without a price carry no dollar value. Amended Form 4s (4/A) are excluded because they restate a filing already counted, and transactions priced above $10,000 per share or worth more than $2 billion are excluded as reporting errors (typically a price filed in cents or a foreign currency). A filing whose purchases exceed twice the company's current market capitalization is also excluded from value (usually an issuer reporting its own share issuance).

Companies counts distinct issuers with at least one purchase filing. A cluster buy is an issuer with three or more purchase filings in the same month, a common proxy for several insiders buying together.

Figures are recomputed daily from the Quantisnow event database. The current month is marked as month to date until it closes; the previous month is recomputed daily through the following month to pick up late filings, then stays fixed.

April 2026: Insider purchase tagging was interrupted for part of this month, so purchase counts and values are incomplete. Form 4 totals are unaffected.

October 2026: An SEC data outage from Oct 5 left this month's Form 4s unread. Purchases and open-market sales were restored from EDGAR afterward, so these figures were rebuilt rather than captured live and may differ slightly from other months. Form 4 totals are unaffected.

Definitions for every column are in the JSON download.