1/ What Happens with More Funds than Stocks? (Madhavan, Sobczyk, Ang)

"Funds differ meaningfully in terms of individual stock holdings, and we examine the factor exposures of the typical fund and the cross section of holdings of different funds."

https://t.co/d6vU4Fgszg

2/ * Data on fund holdings are from Morningstar
* Sample: Jan. 1, 2007 to Dec. 31, 2018
* Only funds with at least 80% of holdings from the Russell 3000 universe are considered
* Mean AUM-weighted expense ratio for mutual funds (ETFs) is 70 bps (14.2 bps) as of Q4 2018

3/ "The holdings of ETFs and active mutual funds across U.S. stocks can be efficiently summarized by approximately 10 canonical funds.

"There is more commonality explained by the first few canonical funds for active mutual funds than for ETFs."

4/ "Commonality among equity mutual funds has remained approximately constant, but there has been increased dispersion in ETF offerings.

"We see no apparent rise in concentration or crowding for mutual funds over the period from January 2007 to December 2018."

5/ "We examine commonality in active mutual funds in Morningstar style box categories. While Value and Blend commonality has remained roughly constant over the period 2007-2018, Growth funds have exhibited a marked increase in crowded positions."