BOJ is a top-10 shareholder of 90% of Japan's stock market

Bank of Japan ETF purchases make it largest holder of Japanese companies

Bloomberg is calling the Bank of Japan 'The Japanese Whale' is the central bank takes increasing stakes in public companies.

The BOJ is a top-10 shareholder in about 90% of the Nikkei 225, they report. Annual purchases are currently at $27.2B.

"The central bank effectively controls about 9 percent of Fast Retailing Co., the operator of Uniqlo stores, and nearly 5 percent of soy sauce maker Kikkoman Corp. It has an estimated shareholder rank of No. 3 in both Yamaha Corp., one of the world's largest makers of musical instruments, and Daiwa House Industry Co., Japan's biggest homebuilder," Bloomberg writes.

The central bank meets again on Thursday and many believe they could boost shares, something that would extend recent gains in the Nikkei. If they double purchases this week, they would be the top shareholder in 40 of the 225 companies by the end of 2017.