The Estimated Value in Cake is designed so that you can not only show how many options / shares an employee or shareholder has in the company, or the % of equity that may represent, we want them to be able to see what their equity could be worth based on the company's most recent valuation. We find that employees in particular find it easier to understand options and how valuable they really can be when they can see it based on a valuation as opposed to just a number of options.
The current share price is calculated using the most recent valuation that has been added under Company -- Valuations and dividing this by the total securities on issue in the company.
This share price is then multiplied by the total granted options that employee has or the total shares held by that shareholder to determine the estimated value of those options or shares based on the most recent company valuation.
It is important to note that this is only an estimate of what they could be worth and doesn't factor in any price payable by the employee upon exercising their options.
If you'd prefer not to display this to your employees or shareholders (one or the other, or both!) you can turn this off using the toggle bar under the 'Valuations visibility settings' in the Company -- Valuations tab as below.