when you say stock portfolio manager it is a version of the truth

The problem is, in the financial sector, "portfolio manager" has a very specific meaning. It is usually someone who has 20 years experience managing millions, if not billions of dollars. So even if you BS about vanguard funds, if the person you are talking to, is even a little bit knowledgeable, they will know you are not a portfolio manager and will probably lead them to think some suspicious things about you. Also portfolio managers make a ton of money and live near financial centers.

It's an ok response on the internet where you don't have to respond to follow up, but in real life it's a lie that will unravel quickly in a conversation unless you are willing read a ton of books on finance, portfolio management, wall street, and willing spin up a crazy web of lies.