OPSEC is the process and practice of Operations Security. Although it has roots in the military, OPSEC can be applied to any venture requiring secrecy and survival, from business security to personal safety. OPSEC is a mindset of critical thinking and safe habits. Read the sidebar below for more information! 
I have just bought a laptop from a private person. I want to use it for installing my cryptocurrency wallets and operating them. As my money is on it, I thought it might be a risk that the person who sold it to me could have infected the laptop with something.
(If I would be hacked my life would be over)
For this reason, I have factory reset it and installed a new OS (Qubes + Whonix). Is there still a risk, or is it the same as I would have bought it in a store?
I have read the rules