Timothy B. Lee:
So who’s driving all this demand for graphics cards? Cryptocurrency miners. To understand the phenomenon, we talked to people active in cryptocurrency mining, and they all told us similar stories: mining Ethereum and other cryptocurrencies has become hugely profitable in recent months, which is why so many people are racing to expand their mining operations. And getting graphics cards is the main bottleneck.
Also noted in the comments is that high end, high power, PSUs are seeing a similar effect.
This is actually a pretty obvious causal chain in retrospect. I think it might actually qualify as a Black Swan. High end computer equipment appreciating in value is not usual economic behaviour, after all.
On a personal note: I find the mining rigs in the article quite fun to look at. Especially the commercial builds shown in the photo from the South Korean electronics store. On the other hand: it’s annoying. I’ve been toying with the idea of building a deep learning rig, which would require the exact same sort of graphics card(s).