Is it really? If a large portion of your net worth is in shares of a single company that you also work for, wouldn't it make sense to sell your shares even if you think the company is going to do well?
Is it really? If a large portion of your net worth is in shares of a single company that you also work for, wouldn't it make sense to sell your shares even if you think the company is going to do well?
I might be more willing to accept a guaranteed £X than a 20% chance of a £10 * X payout, depending on the X. My personal investment philosophy generally would recommend pulling out large single investments into broader funds even though the potential top payout drops.
tldr; You don't hold something because you think it will go up. You open long when it is going up and you think it will continue. The reason for the 90/90/90 statistic is because of mindsets like those facebook employees you mention.
IMO, as soon as you can reasonably take 5 million of the table do so. Taking risks after that is plenty rational.