share
n.
股份;股票[C][(+in)]
stock
n.
(公司的)股票,股份[C][U]
记名股——name share
记名股票——inscribed share/inscribed stock
股份——share stock
股份证书——scrip certificate/stock warrant
感觉上区别不大,不过share偏向于指股份,而stock偏重于指股票这种金融工具