typical Transactions about Position

除去直接买卖(purchase/sale)外，这里有几个常见的transaction，比较容易搞混。在这里，把它们放在一起比较一下。

opening sale
DefinitionA transaction in which the seller's intention is to create or increase ashortpositionin a security or a series of options. opposite of opening purchase.


opening purchase
DefinitionA transaction in which the buyer's intention is to create or increase alongpositionin a security or a series of options. opposite of opening sale.


closing sale
DefinitionA transaction in which the seller's intention is to reduce or eliminate alongpositionin a stock or an option series.


closing purchase
DefinitionA transaction made in order to close out a position.

总结一下，opening就是建仓，closing是平仓。sale的方式来建仓，那肯定是一个空头（short position）;其他的以此类推。