The Fib extension tool is excellent in projecting the 5th intermediate wave for Bitcoin in its bull markets.
First bull market 2011-13: Using the Fib extension tool to extend from intermediate waves (2), (3) and (4) yields the 4.236 extension at $910. Bitcoin went well beyond that to top at $1177 in Nov 2013.
Second bull market 2015-17: Using the Fib extension tool to extend from intermediate waves (2), (3), and (4) yields the 4.236 extension at $13811. Bitcoin went well beyond that to top at $19764 in Dec 2017.
Third bull market 2018-?: Using the Fib extension tool to extend from intermediate waves (2), (3), and (4) yields th 4.236 extension at about $288,000. Bitcoin may again go well beyond that to top in Ken Standfield's 288K to $486 range by May 25, 2022.