A double top chart is a classic bullish reversal, which signals end for bullish rally.
This chart pattern help traders to exist their trades if they go long on certain instrument and get prepared for selling opportunities after the break of neckline. This chart pattern should only be considered when there's existed bullish rally on a timeframe.
And sell trades should strictly be taken only after the break of neckline. Traders can target next demand zones and stop loss above neckline or previous resistance.