"Oversold" is one of those TA buzzwords that get thrown around in the mainstream financial press, and it drives me nuts. It's just another way of saying something's undervalued--but with bitcoin there's absolutely no way to determine that.
People tend to oversimplify what "overbought" and "oversold" mean. They apply an absolute definition like oversold=undervalued, when the indicator itself is
relative.In a ranging market, this makes sense. You can buy when it's oversold at the bottom of the range, and sell when it's overbought.
In a trending market, it makes no sense. Strong price momentum can keep oscillators like RSI glued in overbought or oversold conditions. One example is BTCUSD in 2017. The monthly chart was overbought for the entire year, even going back to late 2016. If you sold based on that, you would have missed the entire bubble:
It's really important to distinguish between these two different conditions, ranging vs. trending. They entail almost opposite applications of RSI and similar indicators.