When a company does a reverse split, it means that they are decreasing the number of shares that are available on the market. This can have different impacts on the market capitalization, depending on how it is done. If the company redeems some of its shares, then the market cap will go down. However, if the company simply decreases the number of outstanding shares without buying any back, then the market cap will stay the same. In either case, the reverse split can have an impact on the price per share, and this is usually what drives investors' decision-making when it comes to these types of events.