Amtrak is the brand name for the service provided by National Railroad Passenger Corporation, a weird quasi-public, ostensibly for-profit corporation. Its stock is all owned by the government, but it's not supposed to be dependent on subsidies to operate.

"it's not supposed to be dependent on subsidies to operate."

I don't think this reflects the current thinking in Washington about Amtrak. I wasn't able to find its P/L history, but has it ever made a profit? I can't remember hearing that it did.

This is quite similar to Deutsche Bahn, the main German railway operator. It’s a private company but all shares are owned by the federal government. They get subsidies (mostly infrastructure cost) but any profit they make goes back into the federal budget.