Many things looked promising (more revenue than expected etc), but the market still questioned Twitter’s long term potential. It’s all about getting more users to get more ad revenue. Twitter doesn’t have any other business model that generates a lot of money.
“monthly active users came in at 241 million, a 30% year-over-year increase but well below expectations”
“on May 7 it’s expected that 454.3 million shares held by all insiders will lose trading restrictions, putting downward pressure on the stock”