How late is Form 4 'real-time' data? Measuring filing delay on 11,241 insider filings

The article examines the delay between insider trades and the corresponding Form 4 filings submitted to the SEC. Insider trades, such as buying or selling shares, generate Form 4 filings which contain both a transaction date (when the insider actually traded) and a filing date (when EDGAR disseminates the form). The article demonstrates how this delay can pose challenges for backtesting financial strategies that rely on insider data.

The study analyzed 11,241 Form 4 filings from July 2026 and found that, on average, these filings are delayed by 2 days from the actual trade date. However, the delay can sometimes extend to 8 years. The distribution of delays varies by transaction type, with sales being filed almost universally within the 2-business-day deadline, while open-market purchases, the most relevant transaction type for insider trading research, are the least punctual.

This means that if a strategy relies on insider purchases, it may suffer from look-ahead bias due to the significant delays in filing those trades. The article emphasizes that a long delay is an observed reporting lag, not a compliance violation, as there are legitimate reasons for extensions under the SEC's rules. To avoid this issue, the study recommends joining on filing date rather than transaction date, as the filing date represents when the information became public.

The full study, including charts and code, is available for those interested in replicating the findings.