it&#x27;s not even that they hold 90% of stocks in the Nikkei 225.<p>It&#x27;s that among 90% of the stocks in the Nikkei 225 (about 203 stocks), the BoJ is one of the top-10 stockholders.  Typically with large US stocks, the top 10 stockholders hold about 1-6% [0] -- so that implies, if the countries are substantially similar, that the BofJ holds 1-6% of 90% of Nikkei 225 stocks, or about 0.9-5% of total stocks in the Nikkei 225.<p>[0] <a href="http:&#x2F;&#x2F;finance.yahoo.com&#x2F;q&#x2F;mh?s=CSCO&amp;ql=1" rel="nofollow">http:&#x2F;&#x2F;finance.yahoo.com&#x2F;q&#x2F;mh?s=CSCO&amp;ql=1</a> -- type in any large stock you can think of; you&#x27;ll probably see Vanguard, T.Rowe Price, State Street, and a couple of other investment firms in the 1-6% range.