SEC MIDAS · Market Structure

How Stocks Actually Trade

Most tools show you price. This one shows you behavior— how orders are cancelled, how much trading happens on hidden (non-displayed) orders, how fragmented trading is into odd lots, and how algorithmic each security is. Built from the SEC's public MIDAS market-structure data set. Informational only — this is not a price forecast.

12,455

Securities Covered

5,944

Stocks

6,511

ETFs

2021 Q1–2026 Q2

Coverage

Algorithmic Intensity

How heavily a security is quoted by algorithms — measured from order cancellations and quoting volume, ranked against similar-size peers.

Institutional Footprint

How much trading happens against hidden (non-displayed) orders — a signal of quiet, worked institutional activity.

Retail Fragmentation

How much trading is split into odd lots (under 100 shares) — often elevated for high-priced, retail-heavy names.

Leaderboards · 2026 Q2 · stocks

Market Turbulence Calendar

Days in the latest quarter when an unusually large number of securities showed anomalous order-cancellation activity at once — a marker of market-wide quoting stress. Single-name spikes appear on each security's page.

2026-06-30190 securities flagged
2026-06-29232 securities flagged
2026-06-26384 securities flagged
2026-06-25688 securities flagged
2026-06-24463 securities flagged
2026-06-23438 securities flagged
2026-06-22368 securities flagged
2026-06-18460 securities flagged

Data is derived from the U.S. Securities and Exchange Commission's MIDAS market-structure research data ("Metrics by Individual Security"), which is public information. This is a data-visualization and educational tool describing historical trading behavior. It is not investment advice and is not a forecast of price or return. Metrics describe order-flow characteristics only.