Shares of computer and gaming-graphics chipmaker Nvidia (NVDA - Get Report) were indicated lower on Friday after DZ Bank downgraded the company to sell from hold, and also lowered its 12-month price target for the second time in less than six months. 

DZ Bank analyst Ingo Wermann lowered his rating on the Santa Clara, Calif.-based company and reduced his price target to $158 a share from $170. His previous price target before his April downgrade was $185 a share.

Analysts have been keeping a watchful eye on Nvidia, which has continued to impress on the rollout and sales of its chips, particularly in the artificial intelligence field. The graphics chipmaker posted quarterly earnings last month that handily beat analysts' estimates.

"Given how dominant Nvidia currently is in the AI training accelerator market, and given how large its chip and software investments in the space remain, it would be a mistake to assume that Cerebras, Intel (INTC - Get Report) or Huawei -- or for that matter, other rivals such as AMD (AMD - Get Report) and Google (GOOGL - Get Report) -- will cause major share losses in the near-term," TheStreet tech columnist Eric Jhonsa wrote last month.

"However, at a time when Nvidia's flagship offering is more than 24 months old, their progress is definitely worth keeping an eye on."

Shares of Nvidia were down 1.89%, or $3.49 a share, at $180.78 in early trading on Friday. 

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