Why I think that this can be called as a Biotech Bubble is because, It has done the same exact thing Financials did in 2007. ie., Moved tooo quick tooo far.
Yes Bio Tech (Healthcare) sector is a defensive sector, but this is not "the normal" on a defensive sector.
What could fuel this bubble burst ? That's up to the Govt , and the Medical Insurances out there. Most Medical Insurance at this point is so frustrated with the high Drug / Healthcare provider prices.
Note : This is not a Doom and Gloom Idea to trade. Its just my opinion - I am personally taking cautious actions with the market, that is reducing the risk to 1% or under in a trade. And focus on the Strong and Weak Sectors, Rather than the mixed bag.
This may not happen until second quarter of 2015, or even mid 2015. While the trend is up, I am still . Until there is a transition.
Related Ideas - Show how trend changes again IMO .