A spike is defined as a late movement in the last 30- 45 minutes of the day away from the range the market has been trading in all day ( session) . Next morning if the market opens within the high and low of the range , one can say the spike has been accepted . if the market starts trading above the spike highs , it is considered bullish. If it is below the spike lows it is bearish. Positions above the spike high if taken in longs will have a stop loss below the spike lows and positions taken below the spike lows will have stops at spike highs