One this run up RSI has been spot on ... In fact if anyone had been trading this they would be slightly ahead if they had bought at oversold or when it dipped below 40 ... And sold at overbought at 70 or higher. One thing to note ... Every stock is different and trends do affect RSI values . for instance on a down trend you can expect the RSI to dip lower to let's say 20 and peak at 50 - 60 depending on the strength of the trend. On a strong up trend it is possible for the RSI to stay at overbought for a period of time.... And for the low or overbought to be much higher 30 - 50.
When using indicators for any stock and even the same stock it always a good idea to look at past performance ....to get a base or a good reading .
A stock that is trading sideways may read differently than when it is trending.
Always confirm indicators with price ... Let's say a trend line .... Does what your indicator is telling you match what you are seeing in price .. Like a break in a trend line
While no one can predict what the stock market or a stock price will do using a weight of evidence approach can increase your odds of success imo.