insider trading

American

noun

the illegal buying and selling of securities by persons acting on privileged information.

insider trading Cultural

The unlawful practice of using information that comes from a source “inside” the business but is not available to the general public to trade on the stock market. This activity is prohibited by law and is policed by the Securities and Exchange Commission.

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In the mid-1980s, several revelations of insider trading rocked Wall Street.

Other Word Forms

Derived Forms

insider trader

noun

Etymology

Origin of insider trading

First recorded in 1965–70

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Kalshi said it would use a risk scoring method to identify markets that appear more at risk of manipulation or insider trading, such as those on national security matters.

From BBC • Jun. 9, 2026

Prediction markets face growing concerns around insider trading as they continue to surge in popularity.

From BBC • Jun. 9, 2026

David Miller, the CFTC’s enforcement chief, has said insider trading on prediction markets is “a real problem.”

From The Wall Street Journal • Jun. 3, 2026

“I think it also underscores just how ripe for insider trading many of these markets are.”

From MarketWatch • May 28, 2026

Paolo’s father was a real estate mogul who had been indicted for insider trading some months ago.

From "Genuine Fraud" by E. Lockhart

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023