IBKR US Equity☆

Held by — the largest Section 13(f) filers reporting a long position in IBKR for 2026-Q1. A LAGGED quarterly snapshot filed up to 45 days after quarter-end; it excludes shorts, options, cash and non-US-listed lines. “% of shares out” uses the reported cover-page share count and is omitted when that denominator is unusable.
In these books — membership is looked up in a small NAMED set of constituent books (listed in that column); a miss means “not in those books”, never “not in any index”. Each book carries the issuer's own as-of, and cadences differ (daily to quarterly).
Congress — members with a disclosed STOCK Act transaction in IBKR, most recent first, from the API's returned window (so the per-member trade counts in the tooltip are counts within that window, not lifetime). Amounts are disclosed RANGES, not exact values, and reports arrive up to 30–45 days late. As disclosed — no causal claim, not investment advice.