NO.PZ2023091802000018
问题如下：
Consider four different futures market transactions between a buyer
and a seller:
I. Both buyer and seller are each taking on a new position (long and
short, respectively).
II. Buyer (seller) is taking on a new
position, but seller (buyer) is offsetting an existing long (short) position.
III. Both buyer and seller are offsetting
existing positions.
IV. An existing short makes delivery to an existing long.
Which of the above causes a decrease in the open interest?
选项：
A.None of the above decrease the open interest.
B.II and IV decrease the open interest.
C.III and IV decrease the open interest.
D.All of the above decrease the open interest.
解释：
Both buyer and seller are each taking on a new position (long and
short, respectively): open interest increases + 1.
Buyer (seller) is taking on a new position,
but seller (buyer) is offsetting an existing long (short) position: no change
in open interest.
Both buyer and seller are offsetting existing
positions: open interest decrease -1.
An existing short makes delivery to an
existing long: open interest decrease -1.
