It’s someone who owns shares in Cloudflare (their market ticker being ‘NET’), but everyone here thinks they’re a financial wonk when talking about big tech and finance so they insist on making it opaque like that. It’s a dumb and cringey trend. Just say “as a Cloudflare shareholder”, I promise you the six bytes you save won’t be missed!

But then I wouldn't know how utterly badass this guy is, shooting around those sweet ticker designations that all us plebs wouldn't recognise.

A somewhat small subset of my net worth is Cloudflare, which has the ticker symbol $NET

TIL that stocks can have a "$" in their code.

They don't. The symbol is NET. But I think Twitter lets you use $ as an alternative to # (hashtag), and people use it specifically in front of stock symbols, and now it's becoming customary to prefix stock symbols with $ everywhere.