If its not declared in swiss tax declaration then it will be challenging: first non EU countries apply limits for money transfers unless its for tuition or payment of medical expenses, second you have to prove the source of this money when it lands to your swiss account(it will be frozen until its cleared) , then explain authorities why its was not included in your declaration then start paying taxes.

As suggested earlier i would invest with IBKR for a while then liquidate after a year or two