.com 4L .com with "ai" ending/starting sales

During Q1 up to now, price of these domain trends have been going up quickly. According to the sales report we can see this clearly:

aitl.com auction $849 4/13/2017 Namejet
lbai.com auction $1,726 4/13/2017 Namejet
ncai.com auction $2,544 3/6/2017 Namejet
eqai.com auction $475 2/19/2017 Godaddy
nwai.com auction $560 2/3/2017 Namejet
atai.com auction $3,200 1/5/2017 Godaddy
aifx.com private $50,700 1/4/2017 Sedo