Not investment advice. Educational reading. See Disclaimer.
L.3 · INTERMEDIATE · 2 MIN
Material Nonpublic Information and the Insider-Trading Line
The single brightest line in investment ethics is also a criminal-law line: you may not trade, or tip others to trade, on material nonpublic information. 'Material' means a reasonable investor would consider it important in deciding to buy or sell -- it would, or could, move the price (a coming earnings miss, an unannounced merger, a failed drug trial, the loss of a huge customer). 'Nonpublic' means it has not yet been broadly disseminated to the market. Information has to be BOTH to be off-limits: public-and-material is just good analysis; nonpublic-but-trivial is harmless. The prohibition exists to keep markets fair -- if insiders and their friends could trade ahead of everyone else, ordinary investors would be permanently, structurally disadvantaged, and trust in the market would collapse. Markets run on the belief that the price reflects information available to all, not a private channel for the connected.
Tomorrow's surprise acquisition, heard from an insider
Yes
No
No -- classic illegal insider trading
An earnings beat, already announced in a press release
Yes
Yes
Yes -- this is just acting on public news
The CEO prefers a certain font in slide decks
No
No
Yes -- nonpublic but immaterial, no price impact
Your own mosaic of public filings + lawful expert calls
Yes (your edge)
Built from public pieces
Yes -- the mosaic theory: legal research
§ 02
Both tests must be met for information to be off-limits: material AND nonpublic. Skilled analysis assembles many public and immaterial pieces into a valuable conclusion -- that is the lawful mosaic theory and it is the whole point of research. What is forbidden is the shortcut: one decisive secret fact, obtained through someone's breach of a duty to keep it confidential.
§ 03
The prohibition reaches far beyond officers and directors. Anyone who receives material nonpublic information through a breach of a duty of confidentiality -- a tippee -- inherits that duty if they knew or should have known the source breached it. The chain matters more than the job title: a friend, a relative, a contractor, a journalist passing a tip down the line can all be liable. Two further traps: direction is symmetric (selling to dodge a loss is exactly as illegal as buying to capture a gain), and merely passing the tip onward without trading yourself (tipping) is itself a violation. The safe response to an apparent leak is not to use it -- it is to refuse it and, in a professional setting, report it.
§ 04
An analyst painstakingly combines public 10-K filings, satellite images of store parking lots they purchased, and lawful interviews with industry consultants (who share no confidential client data) to conclude a retailer's quarter will be strong, then buys the stock before earnings. Is this illegal insider trading?
§ 05
Material plus nonpublic plus a breached confidence equals do not trade and do not tip -- in either direction, regardless of your job title, and even if the call is right. The lawful counterpart is the mosaic theory: an edge built from public and non-confidential pieces is the research process working as designed. Hold the whole path together as one habit: a fiduciary puts the client first, manages conflicts instead of exploiting them, and never converts a secret into a trade. That is the trust the entire market -- and every other analytical skill you learn here -- quietly depends on.
Five questions · AI feedback
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Sit with the ideas.
At a dinner, the CFO of a public company mentions to a friend -- an investor with no role at the company -- that next week's earnings will badly miss guidance, before any announcement. The investor sells their entire stake the next morning, avoiding a large loss when the miss is announced. Why is this illegal insider trading even though the investor does not work at the company?
