New, increased, reduced, exited: how changes are classified

The quarter-over-quarter change engine behind every 'bought' and 'sold' on this site.

Between two quarterly snapshots, each position falls into exactly one bucket: NEW (reported now, absent last quarter), INCREASED (more shares), REDUCED (fewer shares), UNCHANGED (same share count), or EXITED (absent now, reported last quarter). The comparison is on split-adjusted share counts of common-stock positions — never option positions, which are tracked separately.

Why NEW is never "+∞%"

A position that goes from zero to five million shares has no meaningful percentage change, so this site never prints one. NEW is its own state, with the entry weight shown instead — the honest measure of how big the debut was.

What "bought" and "sold" really mean

Strictly, the filings show reported share counts changed. Shares can change for reasons other than open-market trades: in-kind transfers, mergers paid in stock, corporate actions, reporting-entity changes. The classification is still called buying and selling in ordinary usage, but where this site aggregates "institutional buying," it is aggregating reported share increases — the methodology page says so, and unusual cases (a security whose CUSIP changed, a manager whose reporting structure changed) are flagged as NOT COMPARABLE rather than forced into a bucket.

Streaks and persistence

One quarter of accumulation is noise; four consecutive quarters is a pattern. For each manager-security pair the site tracks consecutive quarters of net accumulation or reduction, and for each security the number of consecutive quarters of rising aggregate tracked shares. These persistence measures power the "persistent accumulation" lists — historical description, not prediction.

Amendments

Managers amend filings — sometimes restating the whole table, sometimes adding omitted positions. The change engine always compares the latest accepted version of each quarter, and recomputes downstream statistics when an amendment lands.