According to @KobeissiLetter, market concentration is at historic extremes globally, with the top 5 US stocks now representing about 25% of total US market capitalization, near an all-time high (source: @KobeissiLetter). According to @KobeissiLetter, this roughly 25% share is the fourth-lowest among major world markets, only slightly higher than Canada, India, and Japan (source: @KobeissiLetter).