drop like a hot potato

Most of them remember the wild days back in 1933 when Wall Street manipulators jacked the stock from $2 a share to $28, then let the price drop like a hot potato so that they could rig the market over again.

If you succeed in making your opponent feel that his opinion, should it prove true, will be distinctly prejudicial to his interest, he will let it drop like a hot potato, and feel that it was very imprudent to take it up.