BIG PLAYERS. BIG MOVES.DON’T MISS THEM.
See what leading investors own, catch major reported moves, and understand what matters — without spending hours digging through SEC filings.See what leading investors own, catch major reported moves, and understand what matters — without spending hours digging through SEC filings.
SEC-reported · quarter-end snapshots
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- 2.2M+SEC positions analyzed
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- 28+ yearsof filing history
Investors worth tracking
Explore their portfolios, recent moves and ownership signals — backed by verified SEC filings.
See important ownership moves before the next 13F cycle.
Quarterly 13F filings show what notable investors held at quarter-end. MarketInsiderLab also tracks verified 13D/13G ownership filings, surfacing major stake changes, threshold crossings and activist signals between 13F cycles.
VERIFIED SEC OWNERSHIP MONITORING · 13D + 13G
From portfolio context to what matters now.
Research what notable investors own, understand important changes, and let MarketInsiderLab monitor the investors and stocks that matter to you.
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From raw SEC filing to what it actually means.
MarketInsiderLab turns complex ownership filings into a plain-English explanation — while keeping the original SEC evidence one step away.
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See the relationship, not just the holding.
MarketInsiderLab connects each investor to each stock — showing position history, major changes, portfolio importance and who else owns it.
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Major increases, reductions, exits and re-entries are connected to the position timeline.
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See what changed.
Understand what it could mean.
Pro brings relevant filing changes to your inbox, with verified context to help you quickly assess what may be developing and what deserves a closer look.
Track investors
Choose the notable investors that matter to you and turn research intent into continuous monitoring.
Track stocks
Monitor the companies you care about for meaningful activity from notable investors and ownership filers.
Understand the context
See whether a change continues a pattern, reverses direction or reveals documented ownership intent. Historical context is included when the evidence supports it.
Palantir: an increase after three quarterly reductions
ARK Investment Management reported 3.21 million shares, up 3.29% from Q1. The share count had fallen across the previous three quarterly comparisons. The position represented 2.43% of the reported portfolio, ranked #11.
The useful context: a change of direction worth examining. The filing does not tell us the exact trade dates or what ARK will do next.
Inspect the position history →View the SEC filing →Dated research example: quarter ended June 30, 2026; filed August 14, 2026. Not a live alert.Check the evidence, not just the conclusion.
MarketInsiderLab is built around source-linked SEC evidence, explicit methodology and clear boundaries between reported facts, estimates and interpretation.
Portfolio holdings and ownership events are grounded in the underlying filings.
Filing-based estimates are labeled. Unsupported data is not presented as verified certainty.
We help users investigate evidence without turning it into a trading instruction.