Company logo WIP

Hello!
Been working a bit on a logo, heavily influenced by the ying-yang symbol. Curves should reveal an 'S'. Want it to be modern and startup-related. This is by no means a finished product but more the direction I want to take it in. Company name is Selling Solutions.

Definitely want to keep the white, however the circle fill is up for discussion. Suggestions would be much appreciated! :)

Have a good one!