What is the site where you can watch other people's transactions?

This whale just went all in — opened a huge long position on $ETH with 50x leverage, amounting to $150 million and an entry at $1884.4 (liquidation at $1839).

Not stopping there, he also opened a long position on $BTC with 20x leverage, position size of $25.5 million, entry at $82,206.5 (liquidation at $62,640).

Does he know something that we don't, or is this just pure madness?