Is Dash 2x speed?

@JeremyECrawford Is Dash (2x speed) in and of itself or does it just allow you to move your speed a second time during your turn?

— Tyger Bryte (@Tyger_Bryte) May 25, 2016

The Dash action extends your move by an amount equal to your speed. #DnD https://t.co/ItCI3eXqtM

— Jeremy Crawford (@JeremyECrawford) May 25, 2016

@DnDPaladinif that was the case then rogues wouldn’t dash 4x their speeds. like you said in sage advice ! it would be 3x Rogue: move (30 ft.), Dash (30 ft.), and Dash with Cunning Action (30 ft.).

— Jeremy Crawford (@JeremyECrawford) May 25, 2016

@Tyger_Bryte @DnDPaladinI would think that’s only 3x? Move + Dash = 2 x speed, +Dash2 = + Speed again for total of 3x speed? It's 3, not 4.

— Jeremy Crawford (@JeremyECrawford) May 26, 2016