It is easy to explain this :
During 2017 the Bitcoin price skyrocketed and it got the attention from speculators and traders all over the world. Everyone with a bit of cash wanted to get in on the action and they knew very little about Bitcoin, so they jumped on the internet and started to Google to find out more.
The latest spike in the Google Bitcoin searches are just a frantic effort from Stock market traders to look for a quick method to hedge against the falling prices of stocks after the trade wars between the USA and China increased. They are all looking for a new Safe haven to protect their wealth and Bitcoin is seen as a possible option to hedge against these potential losses.