Stop loss is a kind of order to protect loss and also protect profit. For the short 2172 using hourly indicator Y, the stop loss will be a profit protection now since it is getting lower and lower.
For 6pm trade, the stop loss can be lowered to 2150. Remember, it is not a stop and reverse trade, it is just a covering of position. The stop and reverse buy trade signal has also gone lower near to 2172 but still above 2172, and therefore it is considered high still and difficult to reach at 6pm unless there is some fundamental news that can push up the cpo futures price.
Technically, the short 2172 will soon have to do a stop and reverse buy trade if cpo futures price is kept hovering around 2120 to 2140 level. It is expecting the buy signal may happen tomorrow!