What's the difference between BATS Europe and local EU stock markets in terms of order execution?

[persistence]

Let's say I want to buy BASF today. It's a German company and it's traded in Xetra, but there are two different versions of this stock.

Xetra, BASFn
http://investing.com/equities/basf-ag?cid=23434

Bats Europe, BASd
http://investing.com/equities/basf-ag?cid=33024

Tickers and volumes are different, but graphs are identical. When you trade a stock like that, do you have to choose the exchange (Xetra or Bats Europe) by yourself or is it handled automatically by your broker so you can get the best fill?

Thanks!

 

[eusdaiki]

They only execute a small % of daily volume across the different indices.
But thanks to MiFid2 best execution rule the prices should follow each other very closely... even if it isn't as liquid as the main exchange.


https://www.batstrading.co.uk/

 

[persistence]

@eusdaiki, thanks. So they do handle the execution and I don't need to specify the exchange manually.

 

[eusdaiki]

most brokers offer some kind of smart router... but even if routed manually you do have some protection from the market's rules...

If you're taking liquidity on a retail platform it should make little or no difference.
If you're working on an institutional system or optimizing an execution algo, then you need to worry about micromanaging such little details, but that probably isn't the case.