"Stop loss orders to sell are set below the current market price and are performed when the sales price "hits" or crosses the specified price threshold." These do exactly what they say they do, stop the loss from getting any greater. I wouldn't use "breach" sounds pretty strange for a price threshold.



Stop Loss Stop losses are used to protect wealth by automatically placing a sell order for your shares when the price of your share drops below a threshold set by you. There are two types of stop losses.
Fixed price stop loss - Creates a sell order - on your behalf - when a fixed price level is crossed by the current ruling price.
Trailing Price stop loss - Creates a sell order - on your behalf - when a variable price level is crossed by the current ruling price. The variable price level trails the high of the share's ruling price by a fixed amount or a percentage.