The Donchian Channel by Richard Donchian is a simple band system showing an N-day highest high, N-day lowest low, and a midpoint line between them.
The N days start from yesterday, so a day which is a new N-day high or N-day low will break out of the channel. This is taken as a bullish or bearish signal (respectively).
Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2014, 2015, 2016, 2017 Kevin Ryde
Chart is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.