How the Mosaic Theory Allows Legal Investing Without Insider Information

A securities law doctrine that lets analysts build investment theses from public scraps without breaking insider trading rules.

By Garret Merkley · Explainer · Jun 11, 2026

Branched from The Legal Definition of Material Non-Public Information in Securities Law

Quick take

The mosaic theory says you can legally piece together non-public details from many public sources to make investment decisions.
It protects research analysts and investors who dig through filings, industry data, and public conversations—without needing confidential tips.
The SEC endorses it, but you must source everything from genuinely public material and never use true inside information.

The mosaic theory is a legal doctrine in securities law that says an investor or analyst can lawfully assemble investment conclusions by combining many pieces of publicly available information—even if no single piece, on its own, would be considered material. The theory protects diligent research from being treated as insider trading, as long as none of the mosaic tiles came from genuinely confidential or non-public sources. It's the legal foundation that allows professional investors to build sophisticated theses without waiting for official announcements or relying on tips.

What Counts as a 'Tile' in the Mosaic

A tile is any piece of information that is genuinely available to the public. This includes SEC filings (10-Ks, 10-Qs, 8-Ks), earnings call transcripts, press releases, industry reports, competitor disclosures, trade publications, conference presentations, patent filings, real estate records, regulatory databases, and even casual public statements by executives at industry events. It also includes information you derive yourself—visiting a store and counting customers, analyzing satellite imagery of parking lots, calculating production from public supply chain data, or inferring trends from hiring announcements and job postings. The key is that you obtained it through your own effort or from a source that was already public.

How the Assembly Works—and Why It's Legal

The mosaic theory rests on the idea that the law prohibits trading on material non-public information, not on trading after you've done superior analysis. If you synthesize ten public data points into a conclusion that the market hasn't yet priced in, you're not violating insider trading law—you're doing your job as an investor. The SEC and courts have endorsed this reasoning because it encourages the kind of rigorous, public-source research that improves market efficiency. A hedge fund analyst might read a company's supply chain disclosures, cross-reference them with shipping data from port authorities, review supplier earnings calls, and examine patent filings to conclude that a product launch is imminent. None of those sources is confidential; the conclusion is the analyst's own insight.

The critical boundary is that even one tile from a non-public or confidential source can taint the entire mosaic. If you've received a tip from someone with inside knowledge—or overheard a conversation you weren't meant to hear—you cannot use the mosaic theory as a shield. The presence of even one piece of material non-public information means you're trading on inside information, period. Courts have consistently held that the mosaic theory does not permit you to mix confidential material with public data and claim the whole thing is lawful.

Why This Matters for Investors and Analysts

The mosaic theory is essential because it draws a clear line between legal research and illegal insider trading. Without it, any investment decision based on a conclusion not yet known to the market could be suspect. With it, professional investors can confidently pursue their edge through public-source research, competitive intelligence, and analytical skill. This doctrine also protects sell-side research analysts at investment banks and brokerages—they can publish reports that synthesize public information without fear of prosecution, even if their conclusions move stock prices. The theory thus encourages the kind of informed, diligent analysis that makes markets more efficient and helps capital flow to the best opportunities.

When the Mosaic Theory Applies—and When It Doesn't

The mosaic theory applies whenever you are making an investment decision based solely on information you have gathered or derived from genuinely public sources. It applies to hedge funds, mutual funds, individual investors, research boutiques, and corporate development teams. It does not apply if you have received material non-public information from any source—an insider, someone with access to confidential information, or even a tip passed along a chain. It also does not apply if you are a corporate insider yourself (officer, director, or employee with access to confidential information); in that case, the mosaic theory cannot rescue you from trading restrictions, because you have a duty not to trade on what you know. Additionally, the mosaic theory protects your *analysis*, not your *conduct*—if you obtained a public tile through illegal means (hacking, theft, wiretapping), the illegality of the acquisition taints everything downstream.

How to Stay on the Right Side of the Mosaic Theory

Document your sources: Keep records showing every piece of information came from a public or properly derived source.
Avoid tips and gossip: Do not accept or act on non-public information from anyone, no matter how casual the conversation.
Use only legitimate public data: SEC filings, news, industry reports, patent databases, and data you gather yourself (not obtained illegally).
Be transparent about your process: If questioned, you should be able to explain how you assembled your thesis from public materials.
Understand your role: If you work inside a company, the mosaic theory does not protect you; you have a fiduciary duty not to trade on confidential information.

Can I use satellite imagery, store visits, or supply chain analysis as tiles in my mosaic?

Yes—these are all legitimate public-source research methods. Satellite imagery of parking lots, store foot traffic counts, supplier announcements, and logistics data are fair game. You're using your own effort and observation, not trading on confidential tips.

What if I overhear a conversation at a conference or restaurant—can I use that?

It depends. If the conversation was public (you were meant to hear it, or it was in a public setting where anyone could listen), it's a legitimate tile. If it was private—someone speaking in confidence or in a closed meeting you weren't authorized to attend—then it's non-public, and you cannot use it.

Does the mosaic theory protect me if I trade on a conclusion the market hasn't figured out yet?

Yes, as long as all your tiles came from public or properly derived sources. The law prohibits trading on material non-public information, not on superior analysis. If you beat the market by connecting public dots better than others, that's legal investing.

Can a company insider use the mosaic theory to justify trading?

No. If you work for the company or have access to confidential information, you have a fiduciary duty not to trade on what you know. The mosaic theory is a defense for outsiders who gather public information, not for insiders.

What happens if I accidentally mix one piece of non-public information into my mosaic?

The entire mosaic becomes tainted. The presence of even one material non-public tile means you're trading on inside information, and the mosaic theory cannot protect you. The law does not allow you to 'separate out' the bad tile and use the rest.

Sources

SEC enforcement actions and guidance on insider trading and the mosaic theory; U.S. v. O'Brien and related case law establishing the mosaic theory doctrine.