That is how almost every trader put their SL/TPs at and that is what the dealers know and almost every time they go for the largest congestion zone of orders (they care about trading volume, not if you make or lose money). And that is why most SLs are triggered. Usually the SL should be way beyond such zones, but unfortunately, if you are wrong and the price moves against your position then your loss will be bigger. If you're right then your SL won't be triggered and you might get some decent profit.