Do you really think AMC is worth $17 billion? It is a shrinking company whose market is shrinking, and its valuation is 55 times its last annual profit. Or what about BSV? It has a market cap of >$3 billion, and is a coin that can be 51%'ed for a few hundred grand per day, and has insane technical specs.
You are right about BSV, but with AMC things are very different. It's all about real estate, and if AMC does not generate income at all, then the shares of this company will continue to grow as long as real estate prices in the United States continue to rise,
(I'm talking about 1,000 cinemas they own and 10,000 screens). As a consequence, after the recession of Covid, the price of their shares slowly returned to normal, although it is possible that the guys from the WSB crowd could have contributed to this.