I find this Chinese article interesting. The writer questions why short, numeric domain names are so hot. The general consensus among speculators is that numeric domain names are short and limited in supply, so their prices should rise.
The writer argues that we must look at the utility value of a domain name. It is the door to a company on the Internet. For this reason, when a number is used as a domain name, it must be something that the general consumers are familiar with and has certain meaning.
The writer gives the following examples: 163.com is good because 163 used to be the number to dial to get online. 360 is good because it means "in all angles". When numeric domain names with no meaning are traded actively, this only constitutes a bubble.
I agree to a certain extent. If I look at the currency market, it's similar too. 95% of currencies traded everyday are not for buying goods or services. They are just for speculation, but the speculation can continue for a long time. So, domain speculation can continue for a long time, as long as new investors continue to come into the market.