Shares of Japan’s largest brokerage sank to its lowest levels since 2012 on Wednesday amid a slew of bad news.

Bad news flow is pushing Nomura's valuation to fresh lows this week. At 0.43 times net assets, the valuations are close to the all-time low set during the European debt crisis in 2011, according to data by Bloomberg. Year-to-date, Nomura's shares have fallen by 17 percent as the brokerage reported its first annual loss in a decade.

Investors are questioning whether chief executive Koji Nagai can turn around a business hit by volatile capital markets and intensified domestic competition. The firm's prospects deteriorated last week after it was slapped with an unusual business improvement order from Japan’s financial regulator for improperly sharing sensitive information. Several Nomura clients dropped the firm from bond deals after news of the order.