Yes, S$ is the symbol for the Singapore Dollar. It's also known as "SGD" on forex markets (the US$ is know as USD, the A$ (Aussie) is AUD)

I am Japanese But SB can stands Standerd Bond (fiinacial words) "K "many time I heard. Letter "K" Stand Kilo = Thousand I some time speak with native Engish speaker3K or 4K as mean of Thousand . Many Understanding Numbers usually we write as 1,000 like this therefore Letter" K" (KILO) can easy to understand amount. I usually see Hk$ or others that is make diffinition bitween US$ and other$. This my opion.