Guide
The disclosure lag: why you read a trade weeks after it happened
The single most important thing to understand about congressional trade data is that it is not live. A trade you read about today may have been made weeks ago — and that gap changes what the number means.
What the lag is
Under the STOCK Act, a member of Congress must report a trade within 30 days of being notified of it, and no later than 45 days after the transaction itself. That means the public record is always looking backwards: when a trade appears in the feed, the decision to buy or sell was made days or weeks earlier, at prices that may no longer exist.
We call the number of days between the transaction date and the filing date the disclosure lag, and we show it on every trade — because it is the difference between reading the data well and being misled by it.
Why it matters
The lag has two big consequences:
- You cannot act on the same information the member had. By the time a purchase is public, the stock may already have moved. Any honest question about whether following Congress beats the market has to measure returns from the filing date — what a member of the public could actually have done — not the transaction date.
- A long lag is itself a signal worth seeing. A trade filed close to the 45-day limit, or late, spent longer out of public view. We surface the price move during that non-public window on each trade, so you can see how a stock behaved before anyone outside the filer knew.
How we handle it
Everywhere it matters, our analysis is built around the lag rather than ignoring it. Performance is measured from the filing date, so the backtest reflects a position a follower could really have taken (see our returns study). Impossible or contradictory dates — a filing dated before the trade, say — are flagged and kept out of "latest activity", so one bad date can't masquerade as fresh news.
None of this is a criticism of any individual member; the lag is baked into the law. It is simply the first thing to keep in mind whenever you read a congressional trade — including the ones in our database.
Frequently asked
How late can a congressional trade legally be disclosed?
Up to 45 days after the transaction (or within 30 days of the member being notified of it, whichever comes first). Many filings arrive close to that limit, and some arrive late.
Does the lag mean the data is unreliable?
No — the filings themselves are accurate public records. The lag just means the data is historical, not live. As long as you measure from the filing date and treat the trade as something that already happened, the record is trustworthy.