Disclosure: I work at EquityZen, a marketplace for pre-IPO shares Every company has different transfer restrictions on their shares/options. Yes they could leg

Disclosure: I work at EquityZen, a marketplace for pre-IPO shares Every company has different transfer restrictions on their shares/options. Yes they could legally block the sale if their by-laws or the share grant agreement allows it. We have somewhat standardized agreements for transferring shares at EquityZen, and we get company approval for all deals.