Millennials are plowing money into these 6 ETFs

The BOTZ ETF invests most of its assets in securities that are part of the Indxx Global Robotics & Artificial Intelligence Thematic Index.

It invests in companies involved in areas such as robotics, automation, artificial intelligence, and autonomous vehicles. Its holdings include Intuitive Surgical (ISRG), Mitsubishi Electric (TYO:6503) and Nvidia (NVDA).

Number of investors: 16,932

Ranking on Robinhood: 88

Source: Global X

The Vanguard Total Stock Market ETF is designed to track the performance of the CRSP US Total Market Index. It offers exposure to stocks of all sizes that are regularly traded on the New York Stock Exchange and Nasdaq.

Number of investors: 23,546

Ranking on Robinhood: 61

Source: Vanguard

The SPDR S&P 500 ETF Trust tracks the S&P 500, offering broad exposure to major US stocks. Its top holdings include Microsoft (MSFT), Apple (AAPL), Amazon (AMZN) and Facebook (FB).

Number of investors: 32,749

Ranking on Robinhood: 49

Source: ETF.com

The ETFMG Alternative Harvest ETF invests the bulk of its assets in securities included in the Prime Alternative Harvest Index. These include cannabis stocks such as Cronos (CRON), Aurora Cannabis (ACB) and Canopy Growth (WEED).

Number of investors: 35,862

Ranking on Robinhood: 46

Source: ETFMG

The Vanguard S&P 500 ETF aims to track the performance of the S&P 500 index. It holds major US stocks such as Johnson & Johnson (JNJ), Exxon (XOM) and Warren Buffett's Berkshire Hathaway (BRK.B).

Number of investors: 40,918

Ranking on Robinhood: 39

Source: Vanguard