> Is supply actively constrained, or is this mostly in anticipation of future shortages?

Both. AI datacenters create immense demand on DRAM, NAND storage, even HDD storage.

Then Sam Altman went ahead and "bought" 40% of the world's DRAM production, by way of secretly approaching both Samsung and SK Hynix (each unaware of the other getting a similar deal), which sent the entire market into a panic and everyone rushed to buy ahead of the anticipated supply shortage.

The kicker is that it wasn't even a proper purchase agreement. Just a non-binding promise of "By 2030 I will have infinite dollars and buy your DRAM".