the problem is that you did not base any of your arguments on actual facts. you just said "if you would have invested 5 months ago, your investment would have grown by a factor of 10." when that is the logic presented, the analogy holds. if you were to give specific reasons why you believe bitcoins grew at that rate AND why the will continue to grow, then it would be a different argument [not that it would necessarily be correct]. however, my point is that when you do not have any sound logic underlying your "investment" it is truly the same as gambling.

A better example is some stock that went up 10X in the last 5 months.