Bitcoin is going up since OXI (no) was said to be the winner by various polls. The small pump started when the first results were given, but it is not settled yet, it can still change.
I didn't think the Greeks conducted exit polls. Can you post some links to where you got your information from please?
The last thing I read said it was 50/50 but it was based on old information. Plus everything can change on the actual voting day.