Falling knife? The bullish case on Twitter

Twitter CEO Dick Costolo at the 2014 International CES on Jan. 8, 2014, in Las Vegas.
Ethan Miller | Getty Images

Not much went right for Twitter on Tuesday.

Its earnings were mistakenly released early.

Its first-quarter revenue and mobile users fell short of expectations. As did its 2015 forecast.

Its stock plunged by 18 percent.

But as most analysts abandoned the shares, a few brave souls on Wall Street stood behind Twitter's long-term story, seeing the drop as a value opportunity. One analyst even upgraded the shares.

Here's why...