What Is This?

Corporate directors, executives, and major shareholders are legally required to disclose every purchase or sale of their own company’s shares within two business days. In the United States, this disclosure happens via SEC Form 4, filed with the Securities and Exchange Commission and immediately available to the public. In the United Kingdom, directors must report dealings under the Market Abuse Regulation. These filings create a publicly accessible record of what the people who know a company best are doing with their personal wealth.

Insider buying is considered more informative than insider selling. A CEO who sells shares might be doing so for any number of personal reasons: paying school fees, diversifying a concentrated position, exercising expiring options. The reasons for selling are numerous and often unrelated to their view of the company’s prospects. But a CEO who reaches into their own bank account and buys shares in the open market has only one reason: they believe the shares are going up. That conviction signal is hard to fake and rarely rewarded with anything other than close attention.

When multiple insiders across a company buy simultaneously, the signal becomes significantly stronger. Multiple executives deciding independently to buy shares at the same time, using their personal funds, at the same price level, tells you something important about their collective assessment of value. Our intelligence pipeline aggregates these transactions, calculates buy-to-sell ratios by sector and by company, and surfaces the most significant clusters of insider conviction.

How to Read It

The primary metric is the buy-to-sell ratio, expressed as the number of open market purchases divided by the number of open market sales over a rolling period. A ratio of 1:1 is neutral. A ratio above 3:1 indicates meaningfully more buying than selling. Ratios above 10:1 are notable. When a ratio reaches 100:1 or higher, you are looking at a genuine signal that insiders across a sector or market are expressing strong directional conviction with their own capital.

It is equally important to distinguish transaction types when reading Form 4 filings. Open market purchases, where the insider pays cash for shares at prevailing market prices, are the highest-quality signal. Option exercises followed by immediate sale are largely irrelevant, as the insider is simply monetising previously granted compensation rather than expressing a view. Automatic plan sales under 10b5-1 arrangements are also less informative since they were pre-scheduled. Filtering to open market transactions only gives you the cleanest picture of insider conviction.

Advanced Applications

Sector-level insider analysis is one of the most powerful applications of the data. When insiders across an entire industry begin buying simultaneously, it tells you something about the outlook for that sector that public information does not yet reflect. They are not necessarily acting on illegal material information. More often, they understand the cyclical dynamics of their industry, the competitive dynamics, and the supply and demand picture in ways that external analysts cannot fully replicate. Their collective behaviour is a form of aggregated expert opinion.

UK market insider data deserves specific attention because it captures a different type of transaction. Unlike US markets, UK director dealings often involve smaller companies where a single director buying represents a much larger proportion of the free float. When a FTSE 250 company shows five directors buying within a two-week window, that is not merely a signal. It is a material event. The UK data also tends to be less contaminated by mechanistic option exercises because the compensation structures differ.

Timing analysis adds another layer. Academic research has consistently shown that insider buying within 30 days of a stock reaching a 52-week low tends to outperform the market over the subsequent six to twelve months. The best insider buying signals, from a statistical standpoint, combine three factors: open market purchase, stock at or near a multi-month low, and cluster buying by multiple different insiders at the same company.

Practical Example: UK Insiders at 736:1, June 2026

One of the most striking insider data points in recent months has been the UK market’s buy-to-sell ratio, which reached 736:1 during a recent tracking period. To put that in context, for every director in the UK market selling shares in an open market transaction, 736 were buying. This is an extraordinary reading by any historical measure and represents a level of collective insider conviction that the UK market rarely produces.

The signal was particularly concentrated in mid-cap industrial and financial names, where valuations had been depressed by a combination of domestic economic uncertainty and institutional underweighting of UK equities relative to global benchmarks. Directors at these companies, looking at their order books and their forward pipelines, saw a disconnect between what the market was pricing and what they believed the businesses were worth. They acted accordingly.

Contextualising this against the FOMC week dynamics is useful. While US markets were focused on Federal Reserve policy, UK insiders were using any share price weakness during the period of global uncertainty to add to their personal positions. The fact that they were buying through a volatile week, rather than waiting for clarity, suggests their conviction was not conditional on the US macro outcome. That kind of unconditional buying, with personal capital at risk, through macro uncertainty, is about as strong an endorsement as a company can receive from its own leadership.

See Live Insider Activity Data

Our Insider Activity page tracks SEC Form 4 filings and UK director dealings in real time, with sector-level buy/sell ratios, cluster alerts, and filtering by transaction type to surface the highest-quality signals.

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