Green Arrows show when price increases beyond midpoint of the band, it started a significant decline in the market. As of today, it hasn't shown that yet
Red Arrows Show that during those times of market "correction(2000,2007,2008,2018,2020) it exceeded the ATR lows to show a warning sign. Market usually corrects after this, institutions take profit on the bounce, and market increases volatility and then sells off.