I have just seen on a blog, that DeGiro do not accept any US person. Anyway the amsterdamtrader.com blog with some old reviews of DeGiro is very Informative about the market/brokers. The NYEBURGH Pop in Amsterdam, use ABN AMRO Clearing, so that is a Cheaper way to use ABN AMRO PRIME
And Totally forget Saxo Bank. That repriced the CHF in 2014 peoples viritulle/real or what ever posions/fatasy in the little Fairy Tail Country
Interactive Broker and ABN AMRO Clearing/Prime can also be linked acording to IB Web *third-party-intergration.php
http://emspotal.ezeoft.com/rtdata.aspx market data price link from RealTick EMS with XETR and other data fees