Sherman Antitrust Act

I’m reading the book “Why Nations Fail” and in one of the chapters, the author defends the Sherman Antitrust Act stating that it prevents large companies from monopolizing markets.

What is the libertarian outlook on this? I know we’re fundamentally against regulation of all kind, but this act also encourages people to start businesses and enter the market, resulting in overall economic growth

… or does it? What do you all think?