I think its not "new trend" as you mentioned in headline. Bitcoin is doing that for years already, with sometimes pretty big up and down trends. Some people say its cause demand and supply of the coins, some people say specific things that happen can inflict price to go up or down, whales and bears can move the market, along with who many how much factors.
Bitcoin is still here, people still using it, and as I see its growing every year. More people joining, more sites using it, that mean something, and no matter how much bitcoin fall or how much it rise, we are here and bitcoin is fine, working properly.
The bitcoin's long term trend is to be used by more and more people as it offers better functions than conventional fiats.