If you are dealing with large amounts of money, make sure all relevant accounts in those transactions have unique strong passwords and are linked to unique unguessable e-mails with unique strong passwords.
I have a bunch of e-mails for my financial stuff, of the type
iye4d8kkj6rb58j3@gmail.com. If they don't know what account is linked to my Paypal, eBay, Amazon, e-wallets, poker accounts, etc, how can they hack it?
The weakest link for hackers is your personal e-mail that you use a lot and might be know to a lot of people. Make sure that if that gets hacked (e.g. by the infamous "security questions", that in reality are "insecurity questions"), they cannot start resetting passwords in accounts that contain your treasures.
For the rest it basically comes down to you not doing any stupid ****. Security software is overrated. The best security comes from the user being aware.