This should be the BTC purchased by Tether this quarter: Tether announced in May 2023 that it would regularly use 15% of its profits to purchase Bitcoin to enhance reserves.
Tether currently holds a total of 82,983 BTC ($7.68B), making it the 6th largest BTC wallet address. Their overall BTC acquisition cost is approximately $36,222, with current unrealized gains reaching $4.72 billion.