Morgan Staley guy checking if ETF has appetite for a stock

holding, say, $1/2M or $1M one has. Is that putting one stock into a pool, say

AAPL, MSFT, NVDA, GOOG, META like 10 stocks? 

What is pro and cos of this approach?

Is this private exchange fund?

https://www.analystforum.com/t/private-exchange-funds/52212