Dynadot

Dynadot is a domain registrar based in San Mateo, California, started in 2002 by Todd Han, who still runs it. It's been ICANN-accredited since the beginning and has grown into one of the registrars domain investors mention most often, alongside GoDaddy, Namecheap and Porkbun.

The reason investors know it is the toolset. Bulk registration and bulk renewals, an API, folder-based portfolio management, free WHOIS privacy on every name, and pricing that's stayed competitive for two decades. It also runs its own expired-domain auctions and backorders, and an aftermarket marketplace where you can list names for sale or set up a for-sale lander without leaving the registrar.

Like every registrar, it has its quirks. The interface has its own logic, support is ticket-based, and the expired auctions draw a smaller crowd than GoDaddy's. But it's a serious, long-running registrar that a lot of people who own hundreds of names have settled on.

Disclosure: Dynadot is a paid sponsor of NotRenewing.com, which I also run.