$SIREN |4-hour RSI(14) 76.2|Overbought
What is RSI? RSI is calculated using closing prices only. It doesn't include trading volume or reflect intraday wicks.
RSI is based on past prices and describes the strength of a move that has already happened. It can't tell you what to do next.
It's more reliable to work out your position size based on where you'll place your stop loss than to guess.

Crypto markets move fast, so don't take on too large a position.