This is just when there's tech news on Bitcoin. If you want to get ready for bubbles just keep an eye on google trends "how to buy bitcoin". Worked for me, admittedly only once though.
http://archive.fortune.com/magazines/fortune/fortune_archive...
The 16 year old brother of a friend of mine suddenly wanted to buy Ethereum but didn't know what it was. A month before that he wanted to get rich with binary option websites.
I sold him the amount he wanted (30 eur worth at around 380USD/ETH) and then sold all of my ETH.