I'm not surprised it was the biggest, as it's a company that's already known to crypto users, so there's a minimum risk of getting scammed, and they have 56 million users, so a huge community of people behind them. These two things sound promising enough to invest it because reputation + a huge user base almost guarantee the price will skyrocket. But that's a public offering, so it's about selling shares to people. That's what might have gathered attention not only of the crypto community, but of big stock traders as well, since getting into something crypto-related and yet familiar is getting more attractive to them.