First off domaining is not like the stock market, there is liquidity in the stock market, there is little to no liquidity in domaining. Short valuable names like 2,3 and 4 letter/number .coms are where the liquidity is, many here and other places have held a domain for years, never gotten an offer and then sold the name for $25,000. Sometimes people have listed names here where there is no reserve and gotten no bites only to sell the name for four or five figures. If there was liquidity for all names that would not happen.
You can make some analogies to real estate although I do not subscribe to as many similarities as others do. There are enough similarities where the comparison does work.
As far as the deregulation or conflicts of interest.
The players:
ICANN oversees all things domains, they approve new tlds and get a piece of every gtld that is sold. .18 on every .com
Verisign runs the .com registry, they have the contract for .com and .net and make $7.85 for each .com domain
Registrars - GoDaddy is the largest, GoDaddy does also compete with domainers with their NameFind.com, they buy portfolios and sell names to end users. They also own the aftermarket Afternic and they make quite a bit from GoDaddy auctions where expired domains at GoDaddy are sold to the highest bidder.
Aftermarkets - Sedo,Afternic,Flippa, Uniregistry Market, BrandBucket etc... These sites all have different policies and commission rates.
Registries - Donuts, Uniregistry, Radix, Minds & Machines and many more. These companies paid the rights to run certain new gtlds like .store,.sexy,.app and about 1000 more.
Parking Providers - Voodoo, GoDaddy CashParking, Bodis, you can change the nameservers and they host a page for you which shows ads and you earn ppc, you share that revenue with the parking company and Google.
Domain Investors - Some make millions, some loses thousands, most are in the middle, well probably most are in lower middle.
Domain Blogs and Forums - News, editorial,comics, advertising, chat and a little mental masturbation.
Aftermarkets do not provide any data but their own, you do not have to deal with any of them, you can run your own site, use a third party escrow company to handle the payments. Do not use Paypal for anyone you don't know and trust.
You don't have to deal with anyone you don't want to except for the registrar and registry provider, all the rest is who you think best fits your business model.