In order to be able to recognize tax crimes earlier, Hessen wants to improve the exchange of information between tax offices and stock exchanges.

Economics Minister Tarek Al-Wazir (The Greens) brought an initiative to the Federal Council on Friday to change the confidentiality obligation in the Stock Exchange Act.

"The processing of the Cum-Ex scandal clearly shows that this duty of confidentiality is no longer regulated in keeping with the times," explained the minister.

"In many cases, it prevents the stock exchanges, but also the stock exchange supervisory authorities of the federal states, from answering requests for information from the tax authorities."

Doubtful trading strategies could go undetected

The stock exchange and the stock exchange supervisory authority are only allowed to share trading data with the tax authorities if this is in the overriding public interest or serves to prosecute a tax offense, explained Al-Wazir.

This does not apply to normal company and tax audits.

Trading strategies that, like the cum-ex model, only served to avoid taxes, could thus remain undiscovered for a long time.

In “cum-ex” deals, investors used an earlier loophole in the law to cheat the state out of billions for years. Around the dividend cut-off date, shares with (“cum”) and without (“ex”) dividend entitlements were shifted back and forth between several participants. Tax offices reimbursed capital gains taxes that were not paid. In 2012 the tax loophole was closed.