If you are under 5000$ dollars in your account you have to wait at least 3 business days for your funds to settle if you want to trade again,at least that's how my broker account operates
I dont know what your net worth account is in Europe but I'm guessing if it fell below a certain amount you would have such issues as well.
Unless you have a margin account you have to wait 3 days for you funds to clear if you buy and sell a stock before the 3day hold period .. That's how is with ameritade .. Now as far a transferring money .. If you wire money from your bank to Ameritrade those funds are avalible within 1 hour to buy in stock that's not on a "chill" list
Same in Europe, if you are able to trade directly w/o waiting 3 days for clearing then you have a margin account. $BMSN pps are holding some ppl need beer $.
This is for money that is recently deposited into your account. I opened an IRA account for my wife and it was funded this past Sunday, so I must wait 6 business days to buy stocks on the bulletin board, options, or pinks.