I would imagine that the stock market value would take a rather strong dip if a company proclaimed that they revenue would be cut down to 75%. Investments and stock options are not only valued by the companies current ability to survive, but also speculative value.
You make two mistakes:
1 - Assuming every business has investors. The majority do not.
2 - Assuming every business is suited to a global audience. The vast majority are not.
"what does the investors think when a company volentarly leaves the EU market?"
This question has 4 predicates.
1) investors. If no investors then there is no investors that can have an opinion.
2) Company. If no company then no investors, and since you have no investors than point 1 applies.
3) leaves. If the company don't leave the market then the investors can't object to a company is leaving, as such point 1 and point 2 applies.
4) EU market. If the company is not leaving the EU market then the question about what investors will think about a company leaving the EU market is not relevant, and thus point 1, point 2 and point 3 applies.
> Assuming every business is suited to a global audience
That was the question. What does investors assume when investing in a software company such as those ycombinate investors usually invest in, for which HN is a forum created by ycombinate.