What Stocks Do Before Congress Discloses
The STOCK Act gives members of Congress up to 45 days to disclose a trade. That window is a legal blind spot: the trade exists, but the public cannot see it. When a member buys a stock and files two, three, or seventeen weeks later, whatever the stock did in between happened entirely out of view.
So we measured it. For every disclosed purchase we could price, we took the stock’s move from the trade date to the disclosure date, and the S&P 500 over the exact same window for comparison. The result cuts both ways, and neither half is the story you’d expect.
The average pre-disclosure move across 9,894 priced purchases. The S&P 500 moved +1.65% over the same windows. On average, the stocks Congress bought actually trailed the market while the trades sat undisclosed.
That is the honest headline: there is no systematic run-up hiding in the disclosure lag. 53.0% of priced purchases rose at all before disclosure, and only 45.1% beat the index over their window. If you expected the average congressional purchase to quietly moon before the paperwork landed, the data says otherwise.
The interesting part is what happens when members file late.
Do longer lags hide bigger moves?
| Disclosure lag | Purchases | Avg move before disclosure | vs SPY |
|---|---|---|---|
| 0-15 days | 2,640 | +0.23% | -0.21% |
| 16-30 days | 4,711 | +0.57% | -0.92% |
| 31-45 days (deadline) | 2,306 | +0.43% | -0.78% |
| 46-90 days · past deadline | 65 | +5.51% | -0.47% |
| Over 90 days · past deadline | 172 | +14.69% | -13.85% |
Within the legal 45-day window, pre-disclosure moves are small. Past it, they are not: purchases disclosed more than 90 days late moved +14.69% on average before the public ever saw the filing. The longer the paperwork took, the more of the stock’s story had already happened in the dark. Those long windows also span more market, so the index moved plenty too; the point is not that late filers picked winners, it is that lateness hides information, whichever direction it runs.
The biggest quiet run-ups
The averages are tame. The extremes are not. These are the largest pre-disclosure moves on record in our data: purchases whose stock had already run the most by the time the public was allowed to know they existed.
| Member | Ticker | Traded | Disclosed | Lag | Move before disclosure |
|---|---|---|---|---|---|
| Debbie Wasserman Schultz House · FL | NGD | Feb 28, 24 | Jul 1, 25 | 489d | +313.45% |
| Rohit Khanna House · CA · Dependent Child | SMCI | Nov 15, 24 | Dec 5, 24 | 20d | +121.42% |
| Richard Dean McCormick House · GA | MGK | Mar 15, 23 | Sep 17, 25 | 917d | +107.79% |
| Byron Donalds House · FL · Spouse | MPWR | Dec 7, 22 | Nov 8, 24 | 702d | +107.00% |
| Byron Donalds House · FL · Self | MPWR | Dec 7, 22 | Nov 8, 24 | 702d | +107.00% |
| Katie Britt Senate · AL · Spouse | GOOG | Apr 14, 25 | Jan 26, 26 | 287d | +106.60% |
| Byron Donalds House · FL · Self | META | Jul 5, 23 | Nov 8, 24 | 492d | +100.20% |
| Byron Donalds House · FL · Spouse | META | Jul 5, 23 | Nov 8, 24 | 492d | +100.20% |
| Richard Dean McCormick House · GA | COST | Mar 15, 23 | Sep 17, 25 | 917d | +98.29% |
| Richard Dean McCormick House · GA | MSFT | Mar 15, 23 | Sep 17, 25 | 917d | +92.14% |
Some of these lags run to hundreds of days, well past the statutory deadline. A few sit comfortably inside it and still saw the stock move double digits before the filing landed. Adjacent rows that look identical are separate line items from the same filing (a member’s own account and a spouse’s, for example). None of this proves anyone traded on something they should not have. What it shows, precisely, is how much price action the disclosure system lets accumulate before the public gets to look.
For each disclosed purchase with a listed ticker, we take the nearest trading-day close on or after the trade date and the nearest close on or after the disclosure date, and compute the percent change between them, with SPY over the identical window for comparison. Windows that end after our latest price bar are excluded, as are trades outside our price coverage (bonds, foreign listings, and some small caps are not covered; roughly 60% of all disclosed purchases are priceable). The sample runs from late 2022 to the present, a broadly rising market, which is part of why the index is hard to beat over these windows. Two more honesty notes: one prolific filer (Ro Khanna, whose family-trust filings itemize many small line items) accounts for a majority of priced purchases; excluding his trades, or weighting each member equally, the conclusion does not change, purchases still trail the index on average. And this is a description of what prices did, not a strategy: nobody trading on public disclosures could have captured this window, and our own backtests deliberately enter only after disclosure.
Coldpine’s compliance board tracks who reports late, and now what each stock did in the meantime, on every disclosed trade.
Coldpine is a publisher of intelligence on public Congressional disclosures. The pre-disclosure move is a descriptive, point-in-time measure of price changes during the disclosure window. It is not a return anyone earned or could have earned by following disclosures, not evidence of trading on nonpublic information, and not investment advice. Amounts in filings are disclosed as ranges; price coverage is limited to listed tickers with available history.