PacWest Bank experienced a decline in deposits by 9.5% in response to "heightened market and customer fears" surrounding the bank after First Republic Bank was closed by regulators. This caused its stock price to fall from $10.15 to $5.96 over the course of a week.

This is a warning sign for investors, as deposit flight often indicates a lack of confidence in the bank's financial health. The loss of deposits can also impact a bank's ability to lend, potentially leading to a credit crunch and further exacerbating the situation.

The decline in deposits could be due to several factors. First Republic Bank's closure may have spooked depositors, leading them to withdraw their funds from other banks. Additionally, concerns about the broader economic environment or the bank's exposure to certain sectors or industries could also have contributed to the decline.

Investors should closely monitor PacWest Bank's financial performance in the coming months to assess whether this is a temporary blip or the start of a more prolonged decline. It's important to keep in mind that bank stocks can be volatile, and sudden fluctuations in price are not uncommon.