There are several DNA testing companies out there that are excellent for genealogists. These include Ancestry DNA, Family Tree DNA, MyHeritage DNA and 23andMe.
These companies provide match lists of possible relatives, links and hints to the family trees on their sites, tools to compare DNA segments, and ability to download your matches or raw data so that you can work with them offline or upload them to other sites (like GEDmatch).
From a DNA sample, they can provide autosomal, X-DNA, Y-DNA and mt-DNA information, each of which is useful for genealogists in their own way.
These tests sample about 700,000 SNPs out of the approximately 10 million SNPs we have. They were selected because they are the SNPs that vary most between humans. There are almost 3 billion more locations that don't vary among humans.
A whole genome test will test all 3 billion positions. It has come down in price and may be obtained from some companies for less than $1000.
For example, the company YSEQ does a Whole Genome Sequence, where they say:
… but they don't say what it is that makes this "Specifically for Genealogy Researchers".
So my question is if there is anything useful to a genealogist, for the purposes of helping to find their ancestors, that a whole genome test can provide that would provide enough added value over and above the standard autosomal, Y-DNA and mtDNA tests, that will make it worth the purchase?
i.e. Should I get a whole genome test? If so, how will it help me advance my genealogical research?
Would the same hold true for a whole Exome sequencing test?