Twitter closes at a 3-year high (TWTR)

Twitter just hit a three-year high.
Shares have been volatile, but are up significantly in the past year. 
Watch Twitter stock trade in real time here. 
Twitter closed up 3.41% Monday to settle at $3.7.90, its best level in three years. 
Shares got off to a red-hot start in 2018, rallying more than 50% by the middle of March. That move was propelled by a fourth-quarter 2017 earnings report that boasted the company's first-ever net profit. That marked the fifth straight q