TradingKey – Sandisk (NASDAQ: SNDK) plunged 13.47% to $1,150.89 on Friday, October 30, a day after reporting record results that beat its own guidance and announcing an 8-for-1 stock split. Including Thursday’s decline before the report, the stock lost about 18% over two sessions, erasing roughly $39 billion in market value, according to TIKR.

The trigger came from Kioxia, Sandisk’s manufacturing partner in Japan, which warned that the surge in NAND flash prices is fading fast. Memory stocks trade on how quickly prices are rising, not just on price levels, so a slowdown in price growth was enough to outweigh a strong quarter. Overnight trading showed a small recovery to $1,180.04.