Black Friday Slaughter Sale

Entry in progress—BP
     
Wikipedia: Black Friday (1869)
The Black Friday gold panic of September 24, 1869 was caused by a conspiracy between two investors, Jay Gould and his partner James Fisk, and Abel Corbin, a small time speculator who had married Virginia (Jennie) Grant, the younger sister of President Grant. They formed the Gold Ring to corner the gold market and force up the price of that metal on the New York Gold Exchange.
 
(Oxford English Dictionary)
slaughter, n.
8. figurative.
b. A sweeping reduction in the price of goods in order to effect a clearance.
1891   in Cent. Dict.