The popularity of ETFs continues to surge this year. And investors definitely have a type they prefer. Investors poured more than $138 billion into ETFs just in the month of September, says ETF.com. That was the biggest inflow for any month this year — and much of it flowed into big-cap U.S. stocks. But most importantly, more than$930 billion in investors' asset flowed into ETFs this year. And that means 2025 is looking like another record year. Last year, a record $1.1 trillion flowed into ETFs. By year's ...