Index funds

They track major stock indexes such as the Standard & Poor’s 500.

Investors in these funds have

25% of their money riding on the fortunes of smartphone makers, social media companies, online retailers, video streaming services, electric-car manufacturers and software providers for self-driving cars.

Meanwhile, roughly

$2.2 trillion is invested in funds that track the S&P 500, according to S&P Dow Jones Indices. And nearly half (44.3%) of all fund assets are now in index funds, according to Strategas Research Partners.