Siafund trading is now active on https://bitsquare.io/ which is a decentralized exchange, if you're not already aware.  Siafunds are only traded in whole.  In other words, no fractional trading.....it's all or nothing.

I'm not the subject matter expert though, so if you really want to see the true community in action and have full access to everything Sia, you should most definitely find your way over to the sia slack.  Strong, vibrant community with over 1400 members and the devs are active daily

https://slackin.sia.tech/