Not necessarily. Some unscheduled market moving news can trigger some algos to pull liquidity out of the markets, in which case a spike such as this could be sharp. In this instance it looks like a 28 ticks move which is not unusual, although FESX is usually thicker than other markets. In unexpected market moving events, when liquidity suddenly disappears, some stops may not get triggered because nobody can buy or sell at that level. Part and parcel of the risk of trading.