https://www.marketwatch.com/story/john-bogle-has-a-warning-for-index-fund-investors-2017-06-01 https://www.marketwatch.com/story/john-bogle-has-a-warning-f...

https://www.marketwatch.com/story/john-bogle-has-a-warning-for-index-fund-investors-2017-06-01 https://www.marketwatch.com/story/john-bogle-has-a-warning-f... > Bogle pointed out that as indexing increases to a certain point, it opens opportunities for active investors to exploit inefficiencies in the pricing of some stocks. But past that point, wherever it might be — somewhere beyond 75%, in his view — the market could become a dangerous place.