操盘手or 交易员

原来Trader in mandarin can be called 操盘手or交易员. But the formal sounds more proactive and the later sounds passive. Hence 操盘手=active trader, 交易员=passive trader or dealer.
The Professional Trader Course's trainer once said Play shares for living can be called trader or gambler. If make money it is called trader, if lose money it is called gambler

Big boy called 控盘手
Syndicate called 狙击手
Winner retailers called 真有一手
Loser retailers called 炒股燒手
Never say die retailers called 还有一手