Materion Corporation (MTRN) shares plunged 5.43% in intraday trading on Wednesday, following a downgrade by KeyBanc Capital Markets. The significant drop in stock price comes as investors react to the change in analyst sentiment.

KeyBanc lowered its rating on Materion from Overweight to Sector Weight, a move that typically suggests the stock is expected to perform in line with its sector peers. Moreover, the financial services firm removed its previous price target of $115 for Materion's stock, further dampening investor enthusiasm.

The downgrade by KeyBanc, a respected voice in the financial markets, has clearly influenced investor sentiment towards Materion. While the specific reasons behind the downgrade were not immediately clear, such actions often reflect changes in a company's growth prospects, competitive position, or broader market conditions. Investors will likely be watching closely for any additional information or guidance from the company in the wake of this analyst action.