Morgan Stanley (MS) shares plummeted 5.02% during Tuesday's pre-market session, underperforming the broader market. The financial giant's stock price was pressured by a combination of factors, including insider selling activities and a bearish outlook on a key sector.

According to reports, multiple Morgan Stanley insiders offloaded a significant amount of shares over the past year, raising eyebrows among investors. Insider selling can sometimes be interpreted as a lack of confidence in the company's future prospects, although it's not always a definitive signal.

Additionally, Morgan Stanley's decision to abandon its previously bullish stance on the lithium sector added to the negative sentiment. The bank cited concerns over oversupply and potential weaker demand for electric vehicles in the U.S., dashing hopes for a much-anticipated rebound in lithium prices. This move could impact Morgan Stanley's investment banking and trading activities related to the sector.