JPMorgan analyst Paul Coster lowered the firm's price target on Nikola (NKLA) to $35 from $40 and keeps an Overweight rating on the shares.

The reduced year-end 2021 price target reflects the execution risk associated with a "tarnished brand," Coster tells investors in a research note. The analyst, however, expects the Nikola news flow "to be less drama-filled and to turn generally positive" in 2021. The shares have traded down 50% in the last month on news that the General Motors (GM) and Republic Services (RSG) partnerships have been abandoned, Coster says.

He believes Nikola was "prudent" to exit these arrangements, preserving cash for the execution of the Class 8 truck initiative. GM could still play an important role as a second-source supplier of fuel cells, notes Coster.

The analyst expects Nikola to post a video of a functioning Tre in January and he looks for a "steady flow" of updates for the truck in 2021.