Shares on issue = SOI, meaning how many shares are available in the company.
So let's say a company is $5 to begin with... they fall down to $2 and than they raise money/capital raise... at say 100,000,000 shares @ $2 for example.
When/If the company returns to $5 again... The market cap of the company would be much more as extra shares they took on during the capital raise/raising money (100,000,000) shares would now be included in the market cap.
Hopefully thats made sense
Feel free to google it, this is not financial advice by any means, its purely my opinion only and not financial advice.
(20min delay)