Stifel Nicolaus Downgrades IPG Photonics To Hold By: Benzinga via Benzinga March 23, 2015 at 08:25 AM EDT Analysts at Stifel Nicolaus downgraded IPG Photonics Corporation (NASDAQ: IPGP) from Buy to Hold and removed the price target of ... Read More >> Related Stocks: Ipg Photonics Corp