Short Term Trading Week Starting: - 22 May, page-58

I think bitcoins have a promising future, but less upside that ether. A month ago 1 bitcoin could buy over 20 ether, now it can buy around 14, it is expected by end of year 1 bitcoin will only buy 6-8 ether, maybe less and maybe sooner. Eventually ether is expected by many to surpass bitcoins. So no I dont think they are worth a buy, I think they are worth converting to ether, but it maybe better holding both.

Yes you can trade them on exchanges just like shares, my preferred one with an easy to use interface is cex.io
Here is a screen grab of the BTC/USD trading depth