I just saw that MANTRA recently completed its token upgrade. It turns out it all happened on March 3rd: code changes and a 1:4 split. Most people who had OM on MANTRA Chain or on exchanges that supported the upgrade didn't have to do anything; everything was automated, and the balances updated themselves.

The interesting part is that if someone still has OM on other chains in the Cosmos ecosystem ( like Stargaze or Osmosis), they probably missed out on the 1:4 revaluation. That's why MANTRA recommended doing the IBC bridge quickly before all this happened. I don't know if many people missed that opportunity, but it's an important detail that some overlooked.

Basically, if you were a MANTRA user and paying attention, your balance was automatically multiplied. If not, well... that's what happens when you don't check announcements in time.