Shares of the Detroit company at last check were down nearly 17% to $18.97.
The company missed analyst estimates even as home-loan volumes rose in the first quarter.
Rocket, which went public last August, said the volume of closed loan originations fell in the first quarter from the fourth quarter and that the weakness would continue in the second quarter.
RBC analyst Daniel Perlin cut his price target on Rocket to $26 a share from $30 and maintained his sector-perform rating.
The analyst also reduced his full-year adjusted revenue and earnings estimates to $11.26 billion and $2.17 a share respectively, down from $13 billion and $2.45 a share.
"Our thesis on RKT shares is that the company will continue to take share in the currently fragmented market by underwriting both new purchase loans and refinancing existing ones," Perlin said in research note.
"The company’s target is to reach 25% market share, having built a technology platform designed to handle $500B of annual origination volume."
Jefferies analyst Ryan Carr lowered his price target to $26 from $30, while affirming a buy rating on the shares.
Although Rocket's adjusted earnings missed his forecast given lower volumes, Carr said that this was offset by better efficiencies.
Carr said Rocket appears to be competing on price to win broker adds, which he views as a strategy that will win long term.
He sees "solid visibility" into greater than $2 per share in earnings next year and says headwinds from the "Partner Channel pricing war" are likely temporary, Carr added.
Rocket was discussed by TheStreet’s Jim Cramer during a recent Lightning Round segment on Mad Money.
In February, Rocket Cos. reported fourth-quarter earnings and revenue that exceeded Wall Street estimates.