The TRIN (Trading Index), also known as the Arms Index, measures the relationship between advancing/declining stocks and their respective volume to gauge whether the market is under buying or selling pressure. It is a real-time market breadth oscillator used extensively by stock market floor traders and institutional desks. Pair TRIN with the A/D Line for a comprehensive breadth analysis framework.
TRIN = (Advancing Issues / Declining Issues) / (Advancing Volume / Declining Volume). A TRIN below 1.0 indicates bullish volume breadth (up-volume dominates); above 1.0 indicates bearish breadth (down-volume dominates). Extreme readings often mark short-term reversal points.
The McClellan Oscillator applies a 19-day and 39-day EMA to the daily advance-decline difference, creating a momentum oscillator for <a href="/academy/indicators" class="text-primary hover:underline">market breadth</a> that identifies overbought/oversold conditions at the index level. It is a staple tool for <a href="/market/stocks" class="text-primary hover:underline">stock</a> market analysts tracking the health of major indices. Use the McClellan Oscillator alongside the <a href="/academy/indicators/advance-decline-line" class="text-primary hover:underline">A/D Line</a> and <a href="/academy/indicators/arms-index" class="text-primary hover:underline">TRIN</a> for a complete breadth picture.
The Advance/Decline Line tracks the cumulative difference between the number of advancing and declining stocks, providing a broad measure of market participation that reveals whether rallies or selloffs are broad-based or driven by a few names. It is the foundational <a href="/academy/indicators" class="text-primary hover:underline">market breadth</a> indicator for <a href="/market/stocks" class="text-primary hover:underline">stock</a> index analysis. Use A/D Line divergence from the index to spot potential tops and bottoms within your <a href="/strategies" class="text-primary hover:underline">trading strategies</a>.