Can I also sell EU stocks tax-free on regulated exchanges (like EU ETFs and unlike US stocks)?

Hi,

I have read here that I can get no-taxable capital gains as a Bulgarian resident if I sell UCITS ETFs on EU regulated exchanges (e.g., XETRA). I have also learned that it does not apply to US stocks, even if I sell them on EU regulated exchanges.

Now my question is, how about European stocks (e.g., Siemens as a German stock)? Can I get the gain tax-free, if I sell it on an EU regulated exchange? Do you have a source for that information?

This source (search for "shares, tradable rights") suggests it is the case, is it true? This source also suggests "As of 1 January 2021, the same tax treatment is extended to transactions carried out on equivalent markets outside the European Union as specified in the legislation" – does this mean there is a way to sell US shares tax free?

Thanks in advance!