The three inside down is three candles: a large bullish candle, a small bearish candle (harami, inside the first body), then a bearish candle closing below the first candle's close. The third candle confirms the harami's reversal.
Bulls gradually lose energy at the highs. The harami signals weakening momentum; the third bearish candle breaking the prior low confirms the weakness. More reliable than a standalone harami.
Confirmed reversal signal after an uptrend (win rate 63%). Enter short after the third bearish candle closes. Stop-loss above the first bullish candle's high.
The three candles must appear in sequence and meet all criteria. The third candle closing below the first candle's close is the key confirmation.