Yep, it sure is: https://sharexcoin.com/market/SC_BTC

Last I checked, the high bid was 302 satoshis: now, the high bid's 1021 satoshis. No trades yet, but the order book's filling up nicely.


 

Actually, Sharex was the second exchange to list SC. Cryptoaltex was first.

[EDIT: I had to delete the rest of this post because I misremembered something.]