That's because there is hardly any bubble this time. Last time it $10 to $260 in relatively short time period. Price should be at least at $500 before we can even began to talk about bubble.
I think this is not true...
We had a jump $140 to $200 in about 24 hours, and then another jump again $200 to $260 (and back to $60) in another 24 hours. It was definitely much slower in the weeks and months before that. Now we moved $155 to $195 in about 24 hours, that is definitely not normal growth. The only moments bitcoin had this growth EVER was during the bubbles. (excluding dead cat bounce after a massive crash)
If you compare side by side the April bubble with the current one, you can clearly see where we are. This speed of growth $140 to $200 is pretty much the same as the part of the previous bubble from $60 to $120. What happened next was a mad jump doubling again $120 to $240 in . If this is any similar we can see price skyrocket to over $300 or $350 in the next couple days, then badly crash, probably to $100 or so.
I suppose, if price is rising $200 to $250 in more than a week or so, then we are almost safe, and the bubble may touch $500 as you say, but that is when it burst, not when we "begin to talk about bubble", as we are just in the middle of one.