The difference between SK Hynix $SKHY and Corning $GLW :

SK Hynix: Earnings have already blown up. Q1 revenue +198%, profit margin 72%, PE only 8x. Listed on US stocks in July, valuation recovery is the surest money.
Corning $GLW: Earnings are still on the way. 10x capacity expansion won’t be completed until 2028, now $90 billion market cap, heading toward $1 trillion after completion.
One has already proven itself, waiting for repricing.
One is proving itself, waiting for capacity release.
Every AI server built, SK Hynix makes money from memory, Corning makes money from connectivity. They are not competitors; they are two chokepoints on the same chain.
GPUs will ultimately have to buy HBM from SK Hynix, and buy fiber and glass substrates from Corning.