WHIPSAWN

To operate a whipsaw.

To cause (a trader) to lose potential profit by buying shares just before the price falls, or by selling them just before the price rises.

To defeat someone in two different ways at once.

Of a trade union: to coerce employers into capitulating by bringing them the news that other (more easily convinced) employers have already done so.

(us politics) to accept bribes from multiple parties at once, with the intent of letting down one or more of them.