Adele's 25 is on course to be the fastest-selling UK album ever, according to the Official Charts Company.
The latest release from the Oscar-winning singer has already passed half a million sales after just three days.
Total sales so far this week stand at 538,000, putting it in good stead to become the UK's fastest-selling album.
Adele has already secured the second fastest in Official Charts history, with four days of the chart week left to run.
Only two albums have ever sold more than 500,000 copies in a week. Take That's Progress sold 519,000 in its debut week in November 2010, and Be Here Now by Oasis, the all-time record holder, notched up 696,000 in its first chart week in August 1997.
When Adele's 21 was released in January 2011, it sold 208,000 copies in its first week and passed the 500,000 sales milestone by its fourth week on sale.
It achieved its biggest one-week tally in its 10th week on sale with 258,000 copies sold in seven days.
On the latest Official Chart Update, Adele's 21 has jumped 17 spots to number 12.
Meanwhile, former chart-topper If I Can Dream by Elvis Presley has climbed back up to number two, and Justin Bieber's Purpose is at number three.
One Direction are at number five with fifth studio album Made In The AM.
The special edition of Take That's III - which includes new single Hey Boy - enters the UK Albums Chart at six.
Olly Murs has re-entered at number 10 with the repack of his latest album, Never Been Better.