I don't think that you need a Laptop for trading, any desktop computer would work fine. If you are constantly on the move then you need a laptop computer. Google search you will find good anti virus and vpn.
Having a laptop can help you to stay online in everywhere as long as there is an internet connection available. Besides that, when you are mobile, you can use your mobile phone to connect to the market, and I am sure that it will give you an easy way to check the market anytime. But if you are not always mobile, then you only need a desktop computer so you can online and check or browse information that you want.