From there, going to $500 in six months isn't very farfetch.
Yes but you're cherry picking the start and end points. Not only that but you're extrapolating that really quite unusual line to twice its length assuming we're looking at a log chart. Either use closing or weighted prices, ie. prices you were likely to have been able to buy at.
Okay, a few months ago the price was ~$10. It went up to $265, doubling almost 5 times.
Doubling 6 times would have gotten us beyond $500. Not that the price would remain there,
but I don't find the possibility of reaching this price really bold.
This is Bitcoin. Saying that the price will remain stable (<1%) for the next week would be bold.