Percentage-based pullback zones (23.6 %, 38.2 %, 50 %, 61.8 %, 78.6 %) within a move.
Fibonacci retracements map the sequence of the Italian mathematician Leonardo da Pisa (Fibonacci) onto price moves. Traders anchor the tool between a notable high and low and watch reactions at the 38.2, 50 and 61.8 percent marks — historically frequent turning points for pullbacks. The 61.8 mark (the golden ratio) is considered the most important retracement level. Important: Fibonacci is not magic, it's crowd psychology — the levels work because so many traders use them.
BTC rallies from 60,000 to 70,000 USD. A pullback to 63,820 USD (61.8 % retracement) is bought — typical uptrend continuation.