I've noticed that many newcomers in crypto overlook one of the most useful tools for futures analysis. I'm talking about open interest, or as it's abbreviated in English — OI. It's not just a number; it's a real indicator of how strongly people believe in the current market movement.

Here's the essence: open interest shows the number of active, open positions in an asset. When a trader opens a position, OI increases. When they close it — decreases. Simple logic, but very informative. The difference from volume is that volume counts all trades over a period, while the open interest indicator tracks only the live positions right now.

Why is this important? Because when open interest grows along with the price — it's a signal that new buyers are entering the market, and the trend is likely to continue. If the price is rising but OI is falling, it means positions are closing, people are leaving, and a reversal could be near. This is one of my favorite filters for confirming a trend.

In practice, I see that the open interest indicator works especially well in derivatives markets — futures, options, crypto futures. It shows the real capital that people are willing to risk. Professionals use it precisely to assess market sentiment and understand how seriously participants are holding their positions.

There's an interesting point: open interest updates only at the end of the trading session, whereas volume can be viewed in real time. This needs to be considered when analyzing intraday movements.

When I look at the combination of volume and OI, it provides a complete picture. If both are increasing — it's a strong bullish or bearish signal, depending on which way the price is moving. If volume is up but open interest is down — it's a red flag, and the trend might break. In sideways markets, falling OI usually means traders are simply closing positions while waiting for a clear direction.

Practical tip: I don't look at the open interest indicator in isolation. I combine it with support-resistance levels, moving averages, RSI, patterns. For example, if I see rising OI, high volume, and a bullish signal from moving averages — it strengthens the entry signal. All together, it works much more effectively.

Of course, there are downsides. The indicator isn't universal — on spot stock markets, it's less useful. It requires interpretation alongside other tools and doesn't give 100% guarantees. Like any indicator, it can lag. But combined with other tools, it's a powerful assistant for understanding the true state of the market.

In the end, if you want to understand what's really happening in the derivatives market, open interest is an essential tool. It reveals the true market sentiment and helps avoid false signals. Check this indicator on your charts — I’m sure you'll start seeing the market differently.