Elite Top-Level 4 Letter Domain Name
SXVH.COM (click domain)
Registrar GoDaddy.com
Price Neg
Parking    Uniregistry.com
 
December of 2013 it was CONFIRMED by Goran Duskic, Founder & CEO at WhoAPI (Service for providing information on DOMAINS and WEBSITES) that personally lead the research of 4-LETTER .COM DOMAIN NAMES, and the now widely well known RESULT is that they are ALL registered (taken). He announced "We are out of all 4-letter .com domains names". 
Concluding only 456,976 combinations of come 4-Letter (.COM) TOP-Domain Names Exist.