One way to hold the two uses together: stock can be pictured as a standing supply that a place keeps ready, rather than something bought for one occasion. A stock company in business keeps a standing pool of money, cut into shares that many people hold. A stock company in the theater keeps a standing group of actors, ready for whatever play comes next. The two uses are best kept apart in practice; the shared picture is a memory hook, not a claim that one grew out of the other.
可以用一個畫面把兩個意思串起來：stock 想成「長期擺著、隨時能拿出來用的一批東西」，而不是臨時買來用一次的。商業上的 stock company 常備的是資金——切成一份一份的股份，很多人各持有一小塊。劇場裡的 stock company 常備的是人——同一批演員留著，下一齣戲來了就上。實際使用時兩個意思要分開看，靠上下文判斷；這個共同畫面只是幫助記憶的想法，不是說其中一個是從另一個變出來的。
登入就可以看每一支怎麼連回核心畫面。