The situation for Deutsche Bank investors is going from bad to worse, as shares of the largest bank in Europe have now erased half their value since the beginning of the year over concerns of the bank's possible role in enabling Danske Bank to possible launder more than $200 billion in suspicious money through the Danish lender's tiny Estonian branch.

DB shares dropped as much as 6% in Frankfurt, the largest one-day drop since May 31. A Danske whistleblower said during testimony before the Danish Parliament that a large European lender (which sources identified as Deutsche Bank) had cleared some $150 billion of the suspicious money before severing its relationship with the Estonian branch in 2015 (two years after JPM is believed to have severed its own clearing relationship during a "de-risking" of its dollar-clearing business).

DB shares were headed to an all-time lowest close in recent trade, extending their YTD drop to 48% from their January highs. DB shares were down 3.1% in recent trade, compared with a 1.7% drop in the Stoxx 600 Banks Index.

(Click on image to enlarge)

(Click on image to enlarge)

To be clear, Deutsche Bank isn't a target of the DOJ investigation, or any investigation (at least not that we know of). But given the recent bloodletting across markets, even the slightest negative news could be enough to harm a company's shares.

"In the current environment, the slightest negative news is enough to make people leave risk assets, especially regarding sensitive topics like money laundering," aid Andreas Meyer, portfolio manager at Aramea Asset Management.

As investigators question the correspondent banks that helped Danske move its client's money into the Western financial system, fears are growing that, instead of being treated as unwitting dupes, banks like JPM and DB could be prosecuted as accomplices in what has become the largest money laundering scandal in European history.