EURUSD on D1 at 2017.08.10 00:00. The chart shows: that the fast average has just crossed below the slower of three averages. Short term momentum is carrying the price down and is in the direction of the cross down – a possible second sign of trend change from up to down. Check also the angle of the elbow joint on the short term moving average which if very acute, can be a sign of strength in that direction (potential short). Check the strength of the move, whether there has been a turn on strong resistance, a candlestick pattern, or test/restest off the top bollinger band or 20SMA and consider selling.
The chart is attached.