Premarket Movers｜B. Riley Surged 25%; IRobot Tumbled 23%; DXYZ Fell 8%; Oracle Down 1%

B. Riley Financial shares surged 25% premarket after reporting Q2 profit of $137.5 million, compared with a loss of $435.6 million a year earlier.

iRobot tumbled 23% in premarket after plunging 73% on Monday.

DXYZ fell 8% in premarket after dropping 10% on Monday.

Oracle kept falling, down 1% in premarket, dropping to its lowest levels since early June.