I've noticed that many traders underestimate one of the most useful tools of technical analysis — open interest. Although at first glance it may seem like a complex indicator, in reality, it provides a clear understanding of what is really happening in the derivatives market.

What is happening here? Open interest reflects the total number of active contracts for a specific asset. When two parties enter into a futures contract, the counter increases by one. When someone closes a position, it decreases. Simple and logical. But here’s what’s important: this is not the same as trading volume. Volume shows how many contracts were bought and sold during the day, while open interest indicates the number of positions that remain open. These are two different metrics that complement each other.

Where is this especially useful? Mainly in futures and options markets, including crypto derivatives. Professional traders use this indicator to understand market sentiment and assess how seriously participants are entering positions. High open interest usually indicates good liquidity and genuine interest in the asset.

Now about practice. When open interest grows simultaneously with an upward trend, it’s a signal that new buyers are constantly entering the market — the bullish movement has strength. If interest declines while volume increases, it may mean traders are closing positions and exiting. This is a potential sign of a reversal. In a sideways market, a falling indicator signals that participants are waiting for a clear direction.

What does combining this tool with others provide? If open interest increases along with volume and technical signals (for example, moving averages show an upward impulse), it significantly strengthens the buy signal. Add RSI for additional confirmation — and you already have a more reliable strategy.

The advantages are obvious: it helps assess trend strength, indicates liquidity, and acts as a filter for false signals. But there are also downsides. Data is updated at the end of the trading session, not in real time. Interpretation requires experience and analysis alongside other indicators. And most importantly — it’s not a panacea. Like any indicator, it can lag or give false signals if viewed in isolation from the context.

The key idea: open interest is not an independent tool but part of a bigger picture. Use it together with volume, volatility, and price action. Track how the number of active positions changes, compare it with the trend and volume — and you will start to see the market more deeply. This comprehensive approach truly gives an advantage in derivatives trading. Understanding how open interest works really helps make more informed decisions and avoid common mistakes.