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Transaction Code S

M
Marcus Thorne
Last Updated: January 5, 2026
Plain English Definition

Transaction Code S on Form 4 indicates an open market sale of securities. This is when an insider sells company stock on a public exchange at market prices, which can signal various things depending on context.

The Trader's Take

The Signal

Code S sales can indicate profit-taking, diversification, or concerns about company prospects. However, sales via 10b5-1 plans (Code S) are often routine and less meaningful than discretionary sales.

The Noise

Many Code S sales are automatic via 10b5-1 plans for tax or liquidity needs and don't necessarily indicate negative sentiment.

Actionable Insights

  • 1
    Distinguish between discretionary Code S sales and automatic 10b5-1 plan sales.
  • 2
    Large Code S sales that significantly reduce position size may be more meaningful.
  • 3
    Compare Code S sales to the insider's total holdings—small sales are less significant.
  • 4
    Look for patterns of Code S sales from multiple insiders simultaneously.

Regulatory Context & Context

Transaction Code S is used on Form 4 filings to report open market sales. The SEC requires this code to distinguish sales from other transaction types and ensure accurate reporting of insider trading activity.

Common Misconceptions

Not all sales are bearish—insiders sell for many legitimate reasons like diversification or expenses.

Code S sales via 10b5-1 plans are often pre-planned and less discretionary.

The size and context of Code S sales matter more than the fact that a sale occurred.

Frequently Asked Questions

What does Transaction Code S mean?

Transaction Code S indicates an open market sale, where an insider sells company stock on a public exchange at current market prices.

Are Code S sales always bearish signals?

Not necessarily. Many Code S sales are routine via 10b5-1 plans or for diversification purposes. Context and size matter when interpreting sales.

On This Page

Trader's TakeRegulatory ContextCommon MisconceptionsF.A.Q.

Related Intelligence

Trading Terms
Transaction Code P
Regulatory
Rule 10b5-1
SEC Filings
Form 4

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