The three inside up is three candles: a large bearish candle, a small bullish candle (harami, inside the first body), then a bullish candle closing above the first candle's close. The third candle confirms the harami's reversal.
Bears gradually lose energy at the lows. The harami signals weakening momentum; the third bullish candle breaking the prior high confirms the strength. More reliable than a standalone harami.
Confirmed reversal signal after a downtrend (win rate 65%). Enter long after the third bullish candle closes. Stop-loss below the first bearish candle's low.
The three candles must appear in sequence. The third candle closing above the first candle's close is the key confirmation.