Your answer only rephrases the question. The only way for it to hit $0 is if nobody is willing to buy the stock. This seems unlikely, given that the Bitcoin they're holding, even at 50% of present value, is still worth significantly more than $0.

Microstrategy's average cost of bitcoin is $26,080.

If the price of Bitcoin fell 50% from today's price of $36,404 it would be at $18,202.

They would be down $7878 on their cost per bitcoin, under 30% loss on their total investment.

https://www.cnbc.com/2021/06/21/microstrategy-owns-over-3-bi...

The losses from their bitcoin position can exceed their current market cap.

Their Bitcoin holdings seems to add up to about half their current market cap, so that seems to make no sense.

EDIT: From [1]:

> “As of June 21st, 2021, MicroStrategy holds an aggregate of approximately 105,085 bitcoins, which were acquired at an aggregate purchase price of approximately $2.741 billion and an average purchase price of approximately $26,080 per Bitcoin, inclusive of fees and expenses.”

From [2]:

> Market cap: $6.08 Billion

So ~half, and average purchase price is still substantially below current BTC price.

[1] https://dailyhodl.com/2021/06/23/michael-saylors-microstrate...

[2] https://companiesmarketcap.com/microstrategy/marketcap/