https://www.theglobeandmail.com/investing/markets/stocks/MU-Q/pressreleases/18147735/micron-stock-has-a-long-road-ahead/
"These write-downs hurt Micron's gross margin, but even if you excluded them, gross margin would have still been negative during the third quarter. It's costing Micron more to produce a bit of memory than it can sell it for right now. The company pushes down per-bit manufacturing costs over time by investing in new manufacturing processes, but when prices fall much faster than costs, there's nothing Micron can do but slash production and try to limit the bleeding."