Honestly, the question of which timeframe to choose for the RSI indicator came up for me back when I started trading. And I quickly realized—there's no universal answer; it all depends on how you trade and what you want to achieve.

If you're a scalper or day trader, then the 15-minute chart will be your friend. On it, the RSI indicator catches every price movement, helping to seize short-term opportunities. However, there are downsides—on M5 and M1, there's a lot of noise and false signals; experience and additional filters are needed, or you'll be jumping back and forth pointlessly.

For swing trading, I usually look at the hourly or four-hour chart. The picture is clearer there, short-term trends and pullbacks are visible, and you can hold a position for several days. On the daily chart, RSI shows medium-term trends and reversal points—such trades can be held for a week or two.

And if you're an investor with a multi-year horizon, then weekly and monthly charts are where the real analysis happens. On these timeframes, signals are generated less frequently, but they carry much more weight. Major overbought and oversold zones are more clearly visible.

Key points I pay attention to: first, how long I usually hold a position. Second, what I am looking for—an entry point for the day or a trend for the month. Third, I remember that the smaller the timeframe, the more sensitive the RSI indicator is to any fluctuations, and consequently, the more noise there is. On larger timeframes, market noise is smoothed out, and signals become more reliable.

My advice: analyze multiple timeframes simultaneously. For example, I look at the daily chart to understand the overall direction, then switch to 15 minutes to find an entry point in that direction. This is multi-timeframe analysis, and it works. Start with the timeframes that suit your style, experiment, and you'll find your optimal combination for each asset.