Learn how to read congressional stock trading disclosures under the STOCK Act, identify the most meaningful trades from senators and representatives, and use Diplyzer to track political trading activity.
In 2012, the United States Congress passed the STOCK Act (Stop Trading on Congressional Knowledge Act), requiring sitting senators and representatives to publicly disclose their personal stock trades within 45 days of each transaction. The result: one of the most watched alternative data sets in modern finance.
Members of Congress serve on committees that regulate industries, conduct briefings on national security, and gain advance knowledge of policy changes that affect specific sectors and companies. Their personal investment decisions — now fully public — have attracted intense scrutiny from both financial analysts and the general public.
The STOCK Act created transparency, but the interpretation of that data requires care. Here is why it has attracted significant investor attention:
Committee Assignments and Sector Knowledge A senator sitting on the Senate Finance Committee, the Armed Services Committee, or the Intelligence Committee gains access to non-public information about sectors under their jurisdiction through official briefings, classified hearings, and private conversations with industry leaders and regulators.
Observed Historical Patterns Multiple academic studies and journalistic investigations have documented instances where congressional stock portfolios significantly outperformed market benchmarks. Whether this outperformance reflects information advantages, superior investment acumen, or random variation is actively debated — but the data is public and widely tracked.
Policy Signal Value Even setting aside any information advantage, congressional trading can signal policy direction. A senator on the defense committee significantly increasing defense contractor holdings may signal views on upcoming defense spending decisions.
Each STOCK Act disclosure includes:
| Field | Description |
|---|---|
| Name | The senator or representative who made the trade |
| Office | Their state and chamber (Senate or House) |
| Stock/Asset | The specific security traded |
| Transaction Type | Purchase, Sale, Exchange, or Partial Sale |
| Amount | A range, not an exact figure: $1K-$15K, $15K-$50K, $50K-$100K, $100K-$250K, $250K-$500K, $500K-$1M, $1M-$5M |
| Transaction Date | When the trade occurred |
| Disclosure Date | When it was reported (can be up to 45 days after the trade) |
| Description | Additional notes, including options trades, capital gains disclosures |
Not all disclosures are equally meaningful. Look for:
The amount ranges make exact figures unknown, but "$500K-$1M" or "$1M-$5M" purchases represent meaningful personal capital commitment. Small $1K-$15K trades are often automatic investment plan contributions and carry little signal.
Ask Diplyzer:
"Show me all congressional stock purchases in the last 90 days where the amount range was $500K or higher. Sort by disclosure date."
The most analytically interesting trades occur when:
Committee assignments are public record. Cross-referencing them with trading activity adds an additional analytical layer.
Ask Diplyzer:
"Show me all Senate trades in the defense and aerospace sector in the last 6 months. Which senators made these trades and what are their committee assignments?"
When multiple members of the same committee all buy or sell the same sector within a short window, the convergence carries more signal than any individual trade.
Ask Diplyzer:
"Have multiple senators or house members disclosed trades in [specific sector or company] within the same 30-day period? Show me any clustering patterns in congressional trading activity."
Congressional trades that precede major policy announcements, regulatory decisions, or government contract awards are the most scrutinized. The timing lag (up to 45 days from trade date to disclosure date) means you are often seeing these trades well after they occurred — but the pattern can still be informative for understanding where political capital is flowing.
Both chambers file under the STOCK Act, but there are differences:
Senate — 100 members; trades tend to be larger dollar amounts; more influential on regulatory and tax policy.
House of Representatives — 435 members; more diverse trading activity; often more granular sector representation due to the larger membership.
Diplyzer covers both chambers:
"Show me the most recent stock trades by House of Representatives members. Which sectors are being bought most heavily?"
"Have any senators disclosed cryptocurrency transactions in the last 6 months? Which cryptocurrencies and what amounts?"
45-Day Lag: Disclosure can occur up to 45 days after the transaction. By the time the trade is public, any information advantage (if it existed) may have already been reflected in the price.
No Exact Dollar Amounts: The bracket reporting system means you know the range but not the exact investment. A "$50K-$100K" trade could be $51,000 or $99,000.
Diversified Portfolios: Many lawmakers hold diversified index funds or managed accounts where trading decisions are made by financial advisors — not the lawmakers themselves. Blind trusts and managed accounts are not subject to STOCK Act reporting for the underlying securities.
Legal Use of Public Information: Using publicly disclosed STOCK Act data to inform investment decisions is entirely legal. The filings are public record, designed to be monitored.
The most actionable use of congressional data is as one layer in a multi-signal analysis:
Comprehensive political intelligence screen:
"Show me all congressional stock purchases exceeding $100K in the last 60 days. Group by sector. Which sectors have the most concentrated buying activity? For the leading sector, what is the current technical trend and fundamental outlook?"