I dunno, the number seems pretty relevant to the BTC that I am holding in my wallet. It was significant to my brother in law who sold one to pay for a renovation to his house back when it was $54,000 or so. In relation to HIVE... No, it's not significant at all.
$100k is only about 1% more than $99k. The trend is interesting, but humans get hung up on certain numbers. It seems a lot of people are scared to sell in case they miss out on a big increase. I fully intend to use my $HIVE when I consider it worth doing. Your BIL got to have house stuff done that may not have been possible otherwise, so I can understand him selling.
I don't want to dampen the excitement of others, but there is so much hype around crypto and it may not all be justified. Just my humble opinion :)