This is also known as "hedging" or "single lock" - the same account opened in the same position more than a single and an empty one.

这也被成为“对冲”或者“锁单”——在同一账户里开设相同头寸的多单和空单。

youdao

Take note: respectively on tile and center position, the four corners of the voice of the free is an empty drum.

要注意：分别敲击瓷砖的四角和中心位置，声音空空的就是有空鼓。

youdao

Robinho cut inside before playing a square ball to Kaka, who delivered a beautifully weighted first-time pass that Luis Fabiano, in an onside position, collected before easing past Claudio Bravo and slotting into an empty net.

BBC: Brazil 3-0 Chile

In short, the Republican leadership finds itself in a position analogous to that of Episcopal bishops: They own an august label and increasingly empty churches because they have been chasing off the faithful priests and congregations.

FORBES: As Country Club Republicans Link Up With The Democratic Ruling Class, Millions Of Voters Are Orphaned