Material Non-Public Information

Material Non-Public Information — MNPI for short — is a term from securities law. It refers to information about a company that satisfies two conditions simultaneously: it is not yet public, and it is significant enough that it could noticeably affect a stock’s price. If a trader learns, for instance, before an official announcement, that one company is acquiring another, they possess MNPI. They are not permitted to buy or sell securities on that basis — this counts as insider trading under nearly all stock exchange regulations worldwide and is punishable by law. The term originates from U.S. law, but is practically identical in substance to what is called “inside information” in the EU.

Why MNPI endangers markets

A functioning stock market relies on one basic principle: all investors have the same access to decisive information. Once this no longer holds, investors without insider contacts systematically lose out. They buy or sell at prices that reflect a value they cannot possibly know.

This undermines trust in the market as a whole. When retail investors feel they stand no chance against insiders, they withdraw their money. Regulators such as the U.S. SEC (Securities and Exchange Commission) or the European ESMA therefore regard MNPI violations as a serious threat — not just to individual investors, but to the stability of entire capital markets.

A widespread misconception is that only board members can possess MNPI. In fact, lawyers, consultants, printers of annual reports, or IT service providers with access to sensitive systems also count as so-called “insiders.” Someone who happens to overhear information at a company party and then buys shares can be held liable just the same.

How to recognize MNPI

Whether a piece of information counts as MNPI depends on two criteria. “Material” means: a reasonable investor would base their purchase decision on it. Classic examples include upcoming quarterly results, planned mergers, an as-yet-unknown lawsuit, or the sudden death of a CEO. “Non-public” means: the information has not yet been disseminated through an official channel — a press release, a mandatory disclosure, an annual general meeting.

The line is not always sharp. If an analyst estimates, based on publicly available figures, that the next quarterly results will be good, they are not trading on MNPI — that is legal analysis. If they receive the same tip directly from the company’s CFO, it is MNPI, even if the CFO mentioned it only in passing.

In practice, companies introduce so-called “blackout periods”: windows of time before the release of quarterly results during which their own employees are not allowed to trade the company’s shares. This reduces the risk of unintentional violations.

MNPI in the AI debate

With the rise of AI systems in the financial industry, this topic is gaining new urgency. Hedge funds and banks are increasingly relying on algorithms that analyze vast amounts of data — including emails, supply chain data, satellite imagery, and mobile phone data. Regulators have since been asking where the line lies between clever analysis of public data and the systematic harvesting of non-public information.

Particularly debated is the use of large language models — the AI systems that power chatbots — being trained on internal company documents. If such systems are fed with as-yet-unpublished data and trading decisions result from it, this could de facto constitute MNPI violations — even if no human has consciously “read” the information.

In 2023, the SEC explicitly warned that MNPI rules apply in a technology-neutral manner: it makes no difference whether a human or an algorithm trades on the information. For companies using AI in financial analysis, MNPI compliance has therefore become a central issue.