S&P500 has a total market cap of $31T. Tesla's current piece of that index is ~2%. A bubble pop would be unlikely to "take the whole economy with it" (thankfully).
When Tesla pops, it will potentially lose 80 or 90% of its values over a couple days/weeks. Even though that's only 2% of the SP500, it will trigger a panic sell for related companies in the same industry, and it might eventually become a macro indicator.