This common expression comes from poker. Look up "poker ante" on the internet and you will understand it. It is used in competitive situations where you have an opponent. You "up the ante" by making a move that increases your potential gains while simultaneously increasing your potential losses. You only "up the ante" if you are confident that you hold a strong hand, although, in poker, you also might up the ante as a bluff.

I agree that it's not that uncommon. By the way, it comes from the world of poker. "The ante" is the money that each player has to put into the pot before the first cards are dealt. If someone "ups the ante", the stakes are higher and there's most risk.

It's really common Oscar. It wouldn't sound strange at all in an informal conversation.

I think it depends on what environments you are in. I hear it in a government, sports, and some card game contexts. It is not super common, but is used more commonly within those specific contexts. I think it is good phrase to know the meaning of, so you can understand it when you hear it, but it is not one of those crucial phrases that you need to be able to use in everyday situations. Feel free to message me if you have questions or are interested in taking a class. Great question!

correction: ...there's more risk.