If you live in a state that’s considered a “work at-will”state, means that your employer can terminate you at any time for any reason. Likewise, you the employee can quit without a two weeks notice at anytime for any reason.
“Work at-will” does not over ride the Federal WARN Act, which for a LAYOFF requires the employer to give you 60 days notice.
There have been suits filed against companies that were in a work at-will state and laid off people with no notice and ended up giving those they laid off back pay of 60 days plus legal expenses. Check out your states gov website on their enforcement of the WARN act vs being laid off. I’m certain Citi would more than be willing to settle out of court for back pay plus legal fees in order to avoid the David vs. Goliath story playing out in court and making the headlines yet once again.