Periodically ethereum has been growing slowly, and most probably this will reach $150 at the earliest. Better is to invest at the earliest. Also ethereum is scheduled for a hard forking and the same got postponed. If that happens it'll surely make a big impact on the price of ethereum.
This is one of the most interesting and most importantly potentially profitable coins when investing for a short time, I see no reason why people would not want to buy it at this price
The reason is they don't wanna bet on the bullish market, so many people have been waiting for another bearish moment again dude.
But basically the short term investment can't be applied on the major cryptocurrency.