We had an upside impulse yesterday. but the 1,1850 level managed to hold price.
Then we had an impulse in the opposite direction which took price back at a lower levels. That whole move confirms a downside direction. Market closing below 1,1800 will mean a sell opportunity with targets at 1,1730.
The 1,1850 remains as a key level on this H1 trend and that's why it could be used for SL placement.