If the share is trading $5 on the stock market with a nominal value of $0.50 how should the investors or shareholders evaluate the profit or loss on the sales of the shares?
In real life how does that work. Can you please explain with the help of an example to have a better idea.
The nominal value of the shares is of no relevance at all. It only exists because the law requires it to exist.
The profit or loss on the sale of shares is simply the difference between the price at which you sold the shares and the price you paid to buy the shares. The market value on the stock exchange changes from day to day and you buy or sell at whatever the share price is on the day on which you buy or sell.