track the level of buying/selling volume. ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏