score:2
A good rule of thumb is to provide supporting evidence to substantiate every statement in your application, even if that particular piece of evidence isn’t specifically referred to in the guide https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/549692/Visitor_Supporting_Documents_Guide_-_English_version.pdf
There’s nothing to prevent you from mentioning your stock options in your covering letter, along with an explanation of why you didn’t include them in the application itself.
In case it’s helpful, you should be aware that there is no ‘interview’ for a UK visit visa application; at the biometric appointment you present the checklist and accompanying documents but there will normally not be an opportunity to present or explain anything not already included.