It got to over $10, and is sitting at $9.50 as I write this. It's a move driven by massive buying. Bitcoin saw this in several stages, leading to spikes, then retracements, levelling out, and next spike. I believe Monero has a big future, so glad to have gotten some before this spike (wish it was more though!).
what is your price estimate by December 2016?
There is a statement that by 2016 XMR will have a billion market cap, what do you think about it?
Never been any good at timing the market. Most people aren't. Do I think it has the potential to reach that level? Yes I do. When will this occur? I do not know. If you believe in it then by the dips, and don't let them freak you out.
Looking at the data, the price would need to rise 10X from current price ($8.25) for Monero to have a market cap of $1B. I personally would give that a couple of years, but again it's just an estimate.
if I have xmr were do I store it?
mymonero.com is one option.