It doesn't happen that way. Because for it to be a single transaction, someone would have to be selling that exact amount of bitcoins in the first place.
If you go to an exchange and buy a large quantity, it will start with orders of the best price, it "eats them" and keeps eating others until it fulfills the buy. So in the exchange you will see a bunch or buys one after the other. BTW, this also means the price is moving...
Which is why "instant" pumps and dumps are not even possible.
If you somehow know the addresses belonging to Tesla, you might point out their buy, and they don't even need to use a single address or wallet for that matter, they might have a bunch of cold wallets like the large whales do.