SolarWinds was a cybersecurity company, so a hack causes people to fundamentally question things. Tesla, on the other hand, doesn't need cars to get hacked for them to self-drive people into barriers or emergency vehicles, and the stock price isn't touched when yet another person dies. Why would a hack change anything?
"hacking tesla" is much broader than crashing a car that's self driving.
It's lifting secret keys that allow criminals to open any Tesla 'till an OTA update, or callback has been rolled out. For days exposing your Tesla+luggage to theft. Or just breaking stuff: imagine the flack of every tesla driver suddenly losing access to navigation or entertainment for weeks. Or camera access: imagine the outrage if hackers can record and publish anything done and said inside and around Teslas in the last months?
Because from a safety perspective, the amount of distracted / drunk / texting drivers who would've otherwise crashed their cars vs the amount of Tesla autopilot caused crashes is one for every 5.89 million miles (from their own website) vs about 500k for humans.
From a purely pragmatic perspective, Tesla's that occasionally and irregularly crash are a way better alternative than terrible human drivers.
It has happened. E.g. the WannaCry attack back in 2017, moved markets severely. Short and most bounced back, but attacks do cause panic.
The good(?) news is that e.g. WannaCry took out large, "boring" companies, like Maersk, or MSD. These companies typically have a low Alpha, low volatility, and people invest in them for long term: decades rather than weeks. Whereas with e.g. Tesla, every fart that Elon makes has an effect on the stocks.
It has to be really severe, like not being to drive your own car for multiple days because of a hack, which needs to be directly caused by their crappy security and not accidental
https://news.ycombinator.com/item?id=38932228
According to one of the comments: "The price of BTC initially jumped 3% on the hacked tweet. That's $25bn+ of market cap."