Is This Fraud?

I am an executive assistant to the CEO/owner of a real estate investment company in the U.S. I have 2 credit cards related to my job - card #1 is a business card where I’m listed as an employee of my boss (card is under boss’s acct but has my name on it) and the card #2 is a company card with my name on it. I was under the impression that card #1 was for boss’s family/personal expenses. Then I realized all of the expenses were being billed back to the company.

The biggest concern I have is card #2. My company card. Per my boss’s instruction I am not to use card #1 and now putting all of my boss’s personal expenses I pay on their behalf on that card (2 examples: the moving company to a new house and the whole family going on expensive international vacations is marked as “travel”). When doing my expense report, I noticed the account my boss expensed it to was the money our investors send their investment money to. I believe my boss invests as well, but I feel like this can’t be legal. My boss signs off on every card purchase in my expense report, and none of the charges pay for me or my activity, unless it’s a business lunch.

I’m getting really nervous after I was instructed to stop using my boss’s personal cards and told to put everything on the company card that has my name on it. Is this fraud, and can I be held liable?